Online Etymology Dictionary

self-effacing (adj.): 1902, from self + effacing (see efface). Self-effacement is recorded from 1866.
self-esteem (n.): 1650s, from self + esteem. Popularized by phrenology, which assigned it a "bump" (Spurzheim, 1815).
self-evident (adj.): 1680s, from self + evident. First attested in Locke's "Essay Concerning Human Understanding."
self-help (n.): 1831, from self + help (n.). Apparently coined by Carlyle. British Self-Help Emigration Society is attested from 1887.
self-image (n.): 1939, from self + image (n.).
self-immolation (n.): also self immolation, 1817, from self + immolation.
self-important (adj.): "having or showing an exaggerated estimation of one's own importance," 1775, from self + important.
self-improvement (n.): 1748, from self + improvement.
self-incrimination (n.): also self incrimination, 1911, from self + incrimination.
self-indulgence (n.): 1753, from self + indulgence.
self-indulgent (adj.): also self indulgent, 1791, from self + indulgent. Related: Self-indulgently.
self-inflict (v.): 1784, from self + inflict. Related: self-inflicted.
self-interest (n.): 1640s, from self + interest (n.).
[Self-interest] is a doctrine not very lofty, but clear and sure. It does not seek to attain great objects; but it attains those it aims for without too much effort. ... [It] does not produce great devotion; but it suggests little sacrifices each day; by itself it cannot make a man virtuous; but it forms a multitude of citizens who are regulated, temperate, moderate, farsighted, masters of themselves; and if it does not lead directly to virtue through the will, it brings them near to it insensibly through habits. [Alexis de Tocqueville, "Democracy in America"]
self-justification (n.): 1775, from self + justification.
self-motivation (n.): 1980, from self + motivation. Related: Self-motivational.
self-pity (n.): 1620s, from self + pity (n.).
self-portrait (n.): 1831, from self + portrait, translating German Selbstbildnis.
self-possession (n.): "command of one's emotions," 1745, from self + possession (n.).
self-preservation (n.): 1610s, from self + preservation. First attested in Donne.
self-reliance (n.): 1883, from self + reliance. First recorded in J.S. Mill.
self-reliant (adj.): also self reliant, 1848, from self + reliant.
self-respect (n.): "proper regard for the dignity of one's person," 1795, from self + respect (n.).
self-righteous (adj.): 1680s, from self + righteous. Related: Self-righteously; self-righteousness.
self-sacrifice (n.): 1711 (implied in self-sacrific'd), from self + sacrifice. Related: self-sacrificing.
self-seeking (n.): "a seeking after one's own benefit (before those of others)," 1580s, from self + seeking (see seek). As an adjective, from 1620s.
self-service (adj.): 1919, in reference to grocery stores, from self + service (n.).
self-serving (adj.): also self serving, 1827, from self + serving (see serve).
self-starter (n.): 1894, of engines, 1960, of persons (especially workers), self + starter. Self-starting (adj.), of motors, is attested from 1866.
self-sufficiency (n.): 1620s, originally an attribute of God (translating Greek autakreia), from self + sufficiency. Of mortals, self-sufficient "able to supply one's own needs" is recorded from 1580s.
self-sufficient (adj.): also self sufficient, 1580s, from self + sufficient. Related: Self-sufficiently.
self-willed (adj.): late 15c., from self + willed (see will).
self-worth (n.): also self worth, 1944, from self + worth (n.).
selfish (adj.): 1630s, from self + -ish. Said in Hacket's life of Archbishop Williams (1693) to have been coined by Presbyterians. In the 17c., synonyms included self-seeking (1620s), self-ended and self-ful.
Let us understand what our own selfish genes are up to, because we may then at least have the chance to upset their designs. [Richard Dawkins, "The Selfish Gene," 1976]
Related: Selfishly; selfishness.
selfless (adj.): "devoted to others' welfare or interest and not one's own," 1825, from self + -less. First attested in Coleridge. Related: Selflessly; selflessness.
selfsame: "identical," early 15c., from self + same. Written as two words until c.1600.
Seljuk: Turkish dynasty of 11c.-13c., c.1600 (Selzuccian), from Turk. seljuq, name of reputed ancestor of the dynasty.
sell (v.): Old English sellan "to give," from Proto-Germanic *saljanan (cf. Old Norse selja "to hand over, deliver, sell;" Old Frisian sella, Old High German sellen "to give, hand over, sell;" Gothic saljan "to offer a sacrifice"), perhaps a causative form of the root of Old English sala "sale." Meaning "to give up for money" had emerged by c.1000.

One of the first things a student of Old English has to learn is that the word that looks like sell usually means "give." An Old English word for "to sell" was bebycgan, from bycgan "to buy." Slang meaning "to swindle" is from 1590s. The noun phrase hard sell is recorded from 1952. To sell one's soul is from c.1570. Sell-by date is from 1972. To sell (someone) down the river is first recorded 1927, but probably from slavery days, on notion of sale from the Upper South to the cotton plantations of the Deep South (attested in this literal sense since 1851). To sell like hot cakes is from 1839.
Sellotape (n.): 1949, proprietary name, Great Britain.
sellout (n.): also sell-out, "corrupt bargain," 1862 (in Mary Chesnut's diary), from sell (v.) + out. Meaning "event for which all tickets have been sold" is attested from 1923. The verbal phrase sell out "prostitute one's ideals or talents" is attested from 1888.
seltzer: 1741, from German Selterser (Wasser), a kind of mineral water, literally "of Selters," village near Weisbaden in Hesse-Nassau, where the mineral water is found.
selvage (n.): mid-15c., "edge of web or cloth so finished as to prevent raveling," apparently literally "its own edge," a corruption of self + edge; on analogy of Middle Flemish selvegge (cf. also Low German sulfegge; Dutch zelfkant, from kant "border;" Middle High German selbende, German Selbend, literally "self-end").
semantic (adj.): 1894, from French sémantique, applied by Michel Bréal (1883) to the psychology of language, from Greek semantikos "significant," from semainein "to show, signify, indicate by a sign," from sema "sign" (Doric sama), from PIE root *dheie- "to see, look" (cf. Sanskrit dhyati "he meditates").
semantics (n.): "science of meaning in language," 1893, from French sémantique (1883); see semantic (also see -ics). Replaced semasiology (1847), from German Semasiologie (1829), from Greek semasia "signification, meaning."
semaphore (n.): "apparatus for signaling," 1816, probably from French sémaphore, literally "a bearer of signals," ultimately from Greek sema "sign, signal" (see semantic) + phoros "bearer," from pherein "to carry" (see infer).
sematic (adj.): 1890, from Greek semat-, comb. form of sema (genitive sematos) "sign" (see semantic) + -ic.
semblance (n.): c.1300, "fact of appearing to view," from Old French semblance, semblant "likeness, appearance," from sembler "to seem, appear," from Latin simulare "to resemble, imitate," from similis "like" (see similar). Meaning "person's appearance or demeanor" is attested from c.1400; that of "false, assumed or deceiving appearance" is from 1590s. Meaning "person or thing that resembles another" is attested from 1510s.
seme (n.): in linguistics, 1866, from Greek sema "sign" (see semantic). Cf. pheme, etc.
Semele: daughter of Cadmus and mother of Dionysus, from Latin, from Greek Semele, a Thraco-Phrygian earth goddess, from Phrygian Zemele "mother of the earth," probably cognate with Old Church Slavonic zemlja "earth," Latin humus "earth, ground, soil."
semen (n.): late 14c., from Latin semen "seed," from PIE *si-so-, reduplication of root *se- "to sow" (cf. Latin serere "to sow," Old Prussian semen "seed," Old Church Slavonic seme, Old High German samo; see sow (v.)).
semester (n.): 1827, from German Semester, from Latin semestris, in cursus semestris "course of six months," from semestris "of six months," from sex "six" + mensis "month."