lax (adj.) Look up lax at Dictionary.com
c.1400, "loose" (in reference to bowels), from Latin laxus "wide, loose, open," figuratively "loose, free, wide," from PIE root *(s)leg- "to be slack, be languid" (cognates: Greek legein "to leave off, stop," lagos "hare," literally "with drooping ears," lagnos "lustful, lascivious," lagaros "slack, hollow, shrunken;" Latin languere "to be faint, weary," languidis "faint, weak, dull, sluggish, languid"). Of rules, discipline, etc., attested from mid-15c.
lax (n.) Look up lax at Dictionary.com
"salmon," from Old English leax (see lox).