Online Etymology Dictionary

empanada (n.): 1939, American English, from Spanish empanada, past participle adjective (fem.) of empanar "to roll and fry."
empanel (v.): late 15c., from Anglo-French empaneller, Old French empaneller; see en- (1) + panel (n.).
empathetic (adj.): 1932, in psychology, from empathy on model of sympathetic and to distinguish it from empathic. Related: Empathetically.
empathic (adj.): 1909, from empathy + -ic. Related: Empathically.
empathise (v.): chiefly British English spelling of empathize; for suffix, see -ize. Related: Empathised; empathising.
empathize (v.): 1924, in psychology, from empathy + -ize. Related: Empathized; empathizing.
empathy (n.): 1903, from German Einfühlung (from ein "in" + Fühlung "feeling"), coined 1858 by German philosopher Rudolf Lotze (1817-1881) as a translation of Greek empatheia "passion, state of emotion," from en "in" (see en- (2)) + pathos "feeling" (see pathos). A term from a theory of art appreciation that maintains appreciation depends on the viewer's ability to project his personality into the viewed object.
emperor (n.): early 13c., from Old French empereor (accusative; nominative emperere; Modern French empereur), from Latin imperiatorem (nominative imperiator) "commander, emperor," from past participle stem of imperare "to command" (see empire).

Originally a title conferred by vote of the Roman army on a successful general, later by the Senate on Julius and Augustus Caesar and adopted by their successors except Tiberius and Claudius. In the Middle Ages, applied to rulers of China, Japan, etc.; only non-historical European application in English was to the Holy Roman Emperors (who in German documents are called kaiser), from late 13c., until in 1804 Napoleon took the title "Emperor of the French."
emphasis (n.): 1570s, from Latin emphasis, from Greek emphasis "significance, indirect meaning," from emphainein "to present, show, indicate," from en "in" (see en- (2)) + phainein "to show" (see phantasm). In Greek and Latin, it developed a sense of "extra stress" given to a word or phrase in speech as a clue that it implies something more than literal meaning.
emphasise (v.): chiefly British English spelling of emphasize; for spelling, see -ize. Related: Emphasised; emphasising.
emphasize (v.): 1828, from emphasis + -ize. Related: Emphasized; emphasizing.
emphatic (adj.): 1708, from Greek emphatikos, variant of emphantikos, from emphainein (see emphasis). Emphatical is earlier (1550s). Related: Emphatically.
emphysema (n.): 1660s, from Modern Latin, from Greek emphysema "swelling, inflation," from emphysan "inflate," from en "in" (see en- (2)) + physan "to blow," from physa "breath, blast" (see pustule).
empire (n.): early 14c., from Old French empire "rule, authority, kingdom, imperial rule," from Latin imperium "rule, command," from imperare "to command," from im- "in" (see in- (2)) + parare "to order, prepare" (see pare).

Not etymologically restricted to "territory ruled by an emperor," but used that way. The Empire, meaning "the British Empire," first recorded 1772 (it officially devolved into "The Commonwealth" in 1931); before that it meant the Holy Roman Empire (1670s). Empire style (especially in reference to a style of dresses with high waistlines) is 1869, from the Second Empire "rule of Napoleon III of France" (1852-70). New York has been called the Empire State since 1834.
empiric (adj.): c.1600, from Latin empiricus "a physician guided by experience," from Greek empeirikos "experienced," from empeiria "experience," from empeiros "skilled," from en "in" (see en- (2)) + peira "trial, experiment," from PIE *per- "to try, risk." Originally a school of ancient physicians who based their practice on experience rather than theory. Earlier as a noun (1540s) in reference to the sect, and earliest (1520s) in a sense "quack doctor" which was in frequent use 16c.-19c.
empirical (adj.): 1560s, from empiric + -al (1).
empiricism (n.): 1650s, in the medical sense, from empiric + -ism. General sense is from 1796.
empiricist (n.): c.1700, from empiric + -ist.
emplace (v.): 1865, back-formation from emplacement.
emplacement (n.): 1802, from French emplacement "place, situation," from emplacer (16c.), from en- "in" (see en- (1)) + placer "to place" (see place (v.)). Gunnery sense attested from 1811.
emplore (v.): variant of implore.
employ (v.): early 15c., from Middle French employer, from Old French emploiier (12c.) "make use of, apply; increase; entangle; devote," from Latin implicare "enfold, involve, be connected with," from in- (see in- (2)) + plicare "to fold" (see ply (v.1)).

Sense of "hire, engage" first recorded in English 1580s, from "involve in a particular purpose," a sense which arose in Late Latin. Related: Employed; employing. The noun is 1660s, from French emploi. Imply, which is the same word, retains more of the original sense.
employe (n.): "person employed," 1834, from French employé (fem. employée), noun use of past participle of employer (see employ).
employee (n.): "person employed," 1850, mainly in U.S. use, from employ + -ee.
employer (n.): 1590s, agent noun from employ.
employment (n.): mid-15c., from Middle English emploien (see employ) + -ment.
emporium (n.): 1580s, from Latin emporium, from Greek emporion "trading place, market," from emporos "merchant, traveler," from en "in" (see en- (2)) + poros "passage, voyage," related to peirein "to pass through" (see port (n.1)).
empower (v.): 1650s, used by Milton, but the modern popularity dates from 1986; from en- (1) + power. Related: Empowered; empowering; empowerment.
empress (n.): mid-12c., emperice, from Old French emperesse, fem. of emperere (see emperor). Queen Victoria in 1876 became one as "Empress of India."
emprise (n.): c.1300, "chivalrous endeavor," from Old French emprise (12c.) "enterprise, venture, adventure, undertaking," from Vulgar Latin *imprensa (source of Provençal empreza, Spanish empresa, Italian impresa), from *imprendere "to undertake," from in- + prehendere "to take" (see prehensile). Archaic in English; in French now with a literal sense "a hold, a grip."
emptiness (n.): 1530s, from empty + -ness.
emption (n.): late 15c., "purchase," from Latin emptionem (nominative emptio) "a buying, purchasing," noun of action from past participle stem of emere "to buy" (see exempt (adj.)).
empty (adj.): c.1200, from Old English æmettig "at leisure, not occupied, unmarried," from æmetta "leisure," from æ "not" + -metta, from motan "to have" (see might (n.)). The -p- is a euphonic insertion.

Sense evolution from "at leisure" to "empty" is paralleled in several languages, e.g. Modern Greek adeios "empty," originally "freedom from fear," from deios "fear." "The adj. adeios must have been applied first to persons who enjoyed freedom from duties, leisure, and so were unoccupied, whence it was extended to objects that were unoccupied" [Buck].

The adjective also yielded a verb (1520s), replacing Middle English empten, from Old English geæmtigian. Related: Emptied; emptying. Figurative sense of empty-nester first attested 1987. Empty-handed attested from 1610s.
empyreal (adj.): late 15c.; see empyrean.
empyrean (n.): mid-14c. (as empyre), from Greek empyros "fiery," from en (see en- (2)) + pyr "fire" (see fire (n.)); confused by early writers with imperial. In Greek cosmology, the highest heaven, the sphere of pure fire; later baptized with a Christian gloss as "the abode of God and the angels."
emu (n.): "large Australian bird," 1610s, probably from Portuguese ema "crane, ostrich," of unknown origin.
emulate (v.): 1580s, back-formation from emulation, or else from Latin aemulatus, past participle of aemulari "to rival." Related: Emulated; emulating.
emulation (n.): 1550s, from Middle French émulation (13c.) and directly from Latin aemulationem (nominative aemulatio), from past participle stem of aemulari "to rival, strive to excel," from aemulus "striving, rivaling" (also as a noun, "a rival," fem. aemula), from Proto-Italic *aimo-, from PIE *aim-olo, from root *aim- "copy" (see imitation).
emulator (n.): 1580s, from Latin aemulator, agent noun from aemulari (see emulation). Computer sense attested by 1965.
emulgent: 1570s (adj.), 1610s (n.), from Latin emulgentem (nominative emulgens), present participle of emulgere "to milk out, drain out" (see emulsion).
emulous (adj.): late 14c., from Latin aemulus, from aemulari (see emulation). Related: Emulously.
emulsification (n.): 1858, noun of action from emulsify.
emulsifier (n.): 1872, agent noun from emulsify.
emulsify (v.): 1853, from Latin emulsus, past participle of emulgere "to milk out" (see emulsion) + -fy. Related: emulsified.
emulsion (n.): 1610s, from French émulsion (16c.), from Modern Latin emulsionem (nominative emulsio), from emulsus, past participle of emulgere "to milk out," from ex- "out" (see ex-) + mulgere "to milk" (see milk (n.)). Milk is a classic instance of an emulsion, drops of one liquid dispersed throughout another.
en bloc: French, literally "in a block."
en masse: French, literally "in mass."
en passant: French, literally "in passing," from present participle of passer "to pass" (see pass (v.)). In reference to chess, first attested 1818.
en route: French, literally "on the way."
en suite: French, literally "as part of a series or set."