interwork (v.)

word-forming element used freely in English, "between, among, during," from Latin inter (prep., adv.) "among, between, betwixt, in the midst of" (also used extensively as a prefix), from PIE *enter "between, among" (source also of Sanskrit antar, Old Persian antar "among, between," Greek entera (plural) "intestines," Old Irish eter, Old Welsh ithr "among, between," Gothic undar, Old English under "under"), a comparative of root *en "in."

A living prefix in English from 15c. and used with Germanic as well as Latinate words. Spelled entre- in French; most words borrowed into English in that form were re-spelled 16c. to conform with Latin except entertain, enterprise. In Latin, spelling shifted to intel- before -l-, hence intelligence, etc.

a fusion of Old English wyrcan (past tense worhte, past participle geworht) "prepare, perform, do, make, construct, produce; strive after" (from Proto-Germanic *wurkjanan); and Old English wircan (Mercian) "to operate, function, set in motion," a secondary verb formed relatively late from Proto-Germanic noun *werkan (see work (n.)).

Sense of "perform physical labor" was in Old English, as was sense "ply one's trade" and "exert creative power, be a creator." Transitive sense "manipulate (physical substances) into a desired state or form" was in Old English. Meaning "have the expected or desired effect" is from late 14c. In Middle English also "perform sexually" (mid-13c.). Related: Worked (15c.); wrought; working.

To work in "insert, introduce or intermix," as one material with another, is by 1670s; hence the figurative sense "cause to enter or penetrate by repeated efforts." To work up (transitive) "bring into some state or condition" is by 1590s of material things, 1690s of immaterial things; hence "bring by labor or special effort to a higher state or condition" (1660s). The meaning "excite, stir up, raise, rouse" is from c. 1600. To work over "beat up, thrash" is from 1927. To work against "attempt to subvert" is from late 14c.

To work out "bring about or procure (a result) by continued labor or effort" is by 1530s. As "bring to a fuller or finished state, elaborate, develop," by 1821. Meaning "to solve, calculate the solution to" a problem or question is by 1848. Intransitive sense "make its way out" is from c. 1600; the sense of "succeed" is attested by 1909. Sense of "exhaust (a mine, etc.) by working it" is from 1540s. The pugilistic sense of "box for practice (rather than in a contest) is by 1927, hence the general sense of "practice, rehearse" (1929) and that of "take exercise" (by 1948).