intergenerational (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.

early 14c., "body of individuals born about the same period" (historically 30 years but in other uses as few as 17), on the notion of "descendants at the same stage in the line of descent," from Old French generacion "race, people, species; progeny, offspring; act of procreating" (12c., Modern French génération) and directly from Latin generationem (nominative generatio) "generating, generation," noun of action from past-participle stem of generare "bring forth, beget, produce," from genus "race, kind" (from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups).

From late 14c. as "act or process of procreation; process of being formed; state of being procreated; reproduction; sexual intercourse;" also "that which is produced, fruit, crop; children; descendants, offspring of the same parent."

Generation gap is recorded by 1967; generation x for the (American) generation born after Baby Boomers (c. 1965 - c. 1979) is from 1991, by author Douglas Coupland (b.1961) in the book of that name; abbreviation gen X is by 1997; generation y is attested by 1994 but did not catch on. Adjectival phrase first-generation, second-generation, etc. with reference to U.S. immigrant families is from 1896. Related: Generational.

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).