Lax
late Middle English (in the sense ‘loose’, said of the bowels): from Latin laxus .
wiktionary
From Middle English lax, from Old English leax(“salmon”), from Proto-West Germanic *lahs(“salmon”), from Proto-Germanic *lahsaz(“salmon”), from Proto-Indo-European *laḱs-(“salmon, trout”). Cognate with Middle Dutch lacks, lachs, lasche(“salmon”), Middle Low German las(“salmon”), German Lachs(“salmon”), Norwegian laks(“salmon”), Danish laks(“salmon”), Swedish lax(“salmon”), Icelandic lax(“salmon”), Lithuanian lašišà(“salmon”), Latvian lasis, Russian лосо́сь(losósʹ, “salmon”), Albanian leshterik(“eel-grass”). Doublet of lox.
Borrowed from Latin laxus(“wide, roomy, loose”).
lax ( uncountable)
etymonline
lax (adj.)
c. 1400, "loose" (in reference to bowels), from Latin laxus "wide, spacious, roomy," figuratively "loose, free, wide" (also used of indulgent rule and low prices), from PIE *lag-so-, suffixed form of root *sleg- "be slack, be languid."
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.
lax (n.)
"salmon," from Old English leax (see lox). Cognate with Middle Dutch lacks, German Lachs, Danish laks, etc.; according to OED the English word was obsolete except in the north and Scotland from 17c., reintroduced in reference to Scottish or Norwegian salmon.
lax (n.)
1951 as an abbreviation of lacrosse.
