From OED: > lox, n. 2 > (lɒks)Pl. lox, loxes.[f. Yiddish laks, f. G. lachs salmon.] > lox, n. 2 > A kind of smoked salmon. > 1941: S. Longstreet Last Man a

From OED: > lox, n. 2 > (lɒks)Pl. lox, loxes.[f. Yiddish laks, f. G. lachs salmon.] > lox, n. 2 > A kind of smoked salmon. > 1941: S. Longstreet Last Man around World xii. 135 “Listen, you lox-eater—until last year you thought herring was the only thing they took from the sea.” > 1950: F. Allen Let. Oct. in G. Marx Groucho Lett. (1967) 73 “At the stage delicatessen..the lox is running good and the cream cheese is spreading easily.” > 1961: B. Malamud New Life (1962) 121 “I'll bet lox to bagels that Gerald will get more for the department.” > 1969: A. Glyn Dragon Variation ix. 293 “He..folded himself on to a stool at the counter, and ordered coffee and a bagel with lox.” > 1972: Times 21 July 12/8 “Where in Paris,..can one enjoy a breakfast of beigles, lox (Yiddish for salmon) and cream cheese?” > 1973: Daily Colonist (Victoria, B.C.) 16 Sept. 35/5 “The bagel..often is eaten with smoked salmon or lox from Nova Scotia.”