Etymology
Advertisement
apart (adv.)

"to or at the side; by itself, away from others," late 14c., from Old French a part (Modern French à part) "to the side," from Latin ad "to" (see ad-) + partem, accusative of pars "a part, piece, a faction, a part of the body" (from PIE root *pere- (2) "to grant, allot"). The first element is probably felt in English as a- as in abroad, ahead (see a- (1)). As an adjective from 1786.

Related entries & more 
Advertisement
come (v.)

elementary intransitive verb of motion, Old English cuman "to move with the purpose of reaching, or so as to reach, some point; to arrive by movement or progression;" also "move into view, appear, become perceptible; come to oneself, recover; arrive; assemble" (class IV strong verb; past tense cuom, com, past participle cumen), from Proto-Germanic *kwem- (source also of Old Saxon cuman, Old Frisian kuma, Middle Dutch comen, Dutch komen, Old High German queman, German kommen, Old Norse koma, Gothic qiman), from PIE root *gwa- "to go, come."

The substitution of Middle English -o- for Old English -u- was a scribal habit before minims to avoid misreading the letters in the old style handwriting, which jammed them together (see U). Modern past tense form came is Middle English, probably from Old Norse kvam, replacing Old English cuom.

Meaning "to happen, occur" is from early 12c. (come to pass "happen, occur" is from 1520s). As an invitation to action, c. 1300; as a call or appeal to a person (often in expanded forms: "come, come," "come, now"), mid-14c. Come again? as an off-hand way of asking "what did you say?" is attested by 1884. For sexual senses, see cum.

Remarkably productive with prepositions (NTC's "Dictionary of Phrasal Verbs" lists 198 combinations); consider the varied senses in come to "regain consciousness," come over "possess" (as an emotion), come at "attack," come on (interj.) "be serious," and come off "occur, have some level of success" (1864). Among other common expressions are:

To come down with "become ill with" (a disease), 1895; come in, of a radio operator, "begin speaking," 1958; come on "advance in growth or development," c. 1600; come out, of a young woman, "make a formal entry into society," 1782; come round "return to a normal state or better condition," 1841; come through "act as desired or expected," 1914; come up "arise as a subject of attention," 1844; come up with "produce, present," 1934.

To have it coming "deserve what one suffers" is from 1904. To come right down to it "get to fundamental facts" is from 1875.

Related entries & more 
come-down (n.)

"setback, sudden change for the worse in one's circumstances," 1840, from verbal phrase; see come (v.) + down (adv.). In 16c.-17c. "total destruction" was expressed metaphorically as "to come to Castle Comedown" (1560s).

Related entries & more 
come-outer (n.)

1850, U.S. slang, "one who abandons or dissents from an established creed or religious custom," from verbal phrase; see come + out (adv.).

Related entries & more 
come-at-able (adj.)

"capable of being approached, attainable," 1680s, from come + at + -able.

Related entries & more 
Advertisement
diagnosis (n.)

"scientific discrimination," especially in pathology, "the recognition of a disease from its symptoms," 1680s, medical Latin application of Greek diagnōsis "a discerning, distinguishing," from stem of diagignōskein "discern, distinguish," literally "to know thoroughly" or "know apart (from another)," from dia "between" (see dia-) + gignōskein "to learn, to come to know," from PIE root *gno- "to know."

Related entries & more 
diagnostic (adj.)

1620s, "of or pertaining to diagnosis," also as a noun, "a symptom of value in diagnosis," from Greek diagnōstikos "able to distinguish," from diagnōstos, verbal adjective from diagignōskein "to discern, distinguish," literally "to know thoroughly" or "know apart (from another)," from dia "between" (see dia-) + gignōskein "to learn, to come to know," from PIE root *gno- "to know." Related: Diagnostics.

Related entries & more 
apartness (n.)

"state of being apart," 1849, from apart + -ness.

Related entries & more 
supervene (v.)
1640s, "come as something additional," from Latin supervenire "come on top of, come in addition to, come after, follow upon," from super "over, upon" (see super-) + venire "to come," from a suffixed form of PIE root *gwa- "to go, come." Related: Supervened; supervening.
Related entries & more 
intervent (v.)
"to come between" (obsolete), 1590s, from Latin interventus, past participle of intervenire "to come between, interrupt," from inter- "between" (see inter-) + venire "to come," from a suffixed form of PIE root *gwa- "to go, come." Related: Intervented; interventing.
Related entries & more