one of the three sons of Noah, from Late Latin Japheth, from Greek Iapheth, from Hebrew Yepheth, perhaps literally "enlargement," from causative form of the stem p-t-h "to be wide, spacious."
Proto-Indo-European root meaning "to yawn, gape, be wide open."
It forms all or part of: chaos; chasm; dehiscence; gap; gasp; gawp; hiatus; yawn.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit vijihite "to gape, be ajar;" Greek khainein, Latin hiare "to yawn, gape;" Old Church Slavonic zinoti "to open (one's mouth);" Russian razinut', Serbo-Croatian zinuti, Lithuanian žioju, žioti, Czech zivati "to yawn;" Old English ginian, gionian "open the mouth wide, yawn, gape," Old Norse gina "to yawn," Dutch geeuwen, Old High German ginen "to be wide open," German gähnen "to yawn."
In English, of rules, discipline, etc., from mid-15c. Related: Laxly; laxness. A transposed Vulgar Latin form yielded Old French lasche, French lâche. The laxists, though they formed no avowed school, were nonetheless condemned by Innocent XI in 1679.