C19: from Yiddish laks, from Middle High German lahs salmon
lox2
/lɒks/
noun
1.
short for liquid oxygen, esp when used as an oxidizer for rocket fuels
Word Origin and History for lox
n.
1934, American English, from Yiddish laks, from Middle High German lahs "salmon," from Proto-Germanic *lakhs-, from the common IE root for the fish, *laks- (cf. Lithuanian laszisza, Russian losos, Polish łosoś "salmon").