lax

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”).

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