lake bed vs bottom

lake bed and bottom both are nouns.

Word	Noun	Adjective	Verb	Adverb
lake bed	Yes	No	No	No
bottom	Yes	Yes	Yes	No

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

Other hypernyms of lake bed include bed.

lake bed (noun)	bottom (noun)
the bottom of a lake	a cargo ship
	the fleshy part of the human body that you sit on
	the lower side of anything
	the lowest part of anything
	a depression forming the ground under a body of water
	low-lying alluvial land near a river
	the second half of an inning; while the home team is at bat

lake bed (adjective)	bottom (adjective)
	situated at the bottom or lowest position
	the lowest rank

lake bed (verb)	bottom (verb)
	come to understand
	strike the ground, as with a ship's bottom
	provide with a bottom or a seat