lake vs loch

lake and loch both are nouns.

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

As nouns, loch is a hyponym of lake; that is, loch is a word with a more specific, narrower meaning than lake:

lake (noun)	loch (noun)
a body of (usually fresh) water surrounded by land	Scottish word for a lake
any of numerous bright translucent organic pigments	a long narrow inlet of the sea in Scotland (especially when it is nearly landlocked)
a purplish red pigment prepared from lac or cochineal