keep down vs suppress

keep down and suppress both are verbs.

Word	Noun	Adjective	Verb	Adverb
keep down	No	No	Yes	No
suppress	No	No	Yes	No

As verbs, suppress is a hypernym of keep down; that is, suppress is a word with a broader meaning than keep down:

Other hypernyms of keep down include crush, oppress.

keep down (verb)	suppress (verb)
manage not to throw up	bring under control by force or authority
place a limit on the number of	lessen to the point of stopping
put down by force or intimidation	put out of one's consciousness
	consciously restrain from showing; of emotions, desires, impulses, or behavior
	come down on or keep down by unjust use of one's authority