lake trout vs trout

lake trout and trout both are nouns.

Word	Noun	Adjective	Verb	Adverb
lake trout	Yes	No	No	No
trout	Yes	No	No	No

As nouns, trout is a hypernym of lake trout; that is, trout is a word with a broader meaning than lake trout:

lake trout: large fork-tailed trout of lakes of Canada and the northern United States
trout: any of various game and food fishes of cool fresh waters mostly smaller than typical salmons

lake trout (noun)	trout (noun)
large fork-tailed trout of lakes of Canada and the northern United States	any of various game and food fishes of cool fresh waters mostly smaller than typical salmons
flesh of large trout of northern lakes	flesh of any of several primarily freshwater game and food fishes