lax

Etymology 1

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.

noun

1. (now chiefly UK dialectal, Scotland) A salmon.

Etymology 2

Borrowed from Latin laxus (“wide, roomy, loose”).

adj

1. Lenient and allowing for deviation; not strict.
   The rules are fairly lax, but you have to know which ones you can bend.
   Society at that epoch was lenient, if not lax, in matters of the passions. 1886, John Addington Symonds, Philip Sidney
2. Loose; not tight or taut.
   The rope fell lax.
   Sreedharan and Mirsa (1973) reported that two lax panicle mutants, designated as nude panicle mutation, were obtained from the M₂ of two rice cultivars. 1979, “Genetical Studies on Dense and Lax Panicles In Rice”, in Japan. J. Breed., volume 29, number 2, page 151
3. Lacking care; neglectful, negligent.
   Prior to this match, Albion had only scored three league goals all season, but Wes Brown's lax marking allowed Morrison to head in their fourth from a Chris Brunt free-kick and then, a minute later, the initial squandering of possession and Michael Turner's lack of pace let Long run through to slot in another. October 1, 2011, Phil Dawkes, “Sunderland 2 – 2 West Brom”, in BBC Sport
4. (mathematics) Describing an associative monoidal functor.
5. (archaic) Having a looseness of the bowels; diarrheal.

Etymology 3

By replacement of the syllable crosse with the cross-shaped letter x.

noun

1. (slang) Lacrosse.
   “I'm not playing lax this term,” Mimah said. 2010, Kate Kingsley, Pretty on the Outside, page 79