propinquity (n.)

late 14c., propinquite, "nearness in relation, kinship," later also "nearness in place, physical nearness" (early 15c.), from Old French propinquite (13c.) and directly from Latin propinquitatem (nominative propinquitas) "nearness, vicinity; relationship, affinity," from propinquus "near, neighboring," from prope "near," with loss of second -r- by dissimilation, from PIE *propro "on and on, ever further" (source also of Sanskrit pra-pra "on and on," Greek pro-pro "before, on and on"), from root *per- (1) "forward," hence "in front of, toward, near." The signification of the suffix -inquus is unclear.

Nothing propinks like propinquity [Ian Fleming, chapter heading in "Diamonds are Forever," 1956; the phrase was popularized 1960s by U.S. diplomat George Ball]