interlinear adj.

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.

"resembling a line, of or pertaining to lines," 1640s, from French linéaire, from Latin linearis "belonging to a line," from linea "string, line" (see line (n.)). Essentially the same word as lineal; "in Latin linearis the original suffix -alis was changed to -aris by dissimilation, but in Late Latin this rule was no longer productive and the formation or re-formation in -alis remained unchanged." [Barnhart].

As "involving the use of lines" from 1840, hence Linear A, Linear B, names given (1902-3) to two related forms of linear Minoan writing discovered 1894-1901 in Crete by Sir Arthur Evans and long defying translation. It is used there in opposition to pictographic.