cotton up vs suck up

cotton up and suck up both are verbs.

Word	Noun	Adjective	Verb	Adverb
cotton up	No	No	Yes	No
suck up	No	No	Yes	No

As verbs, cotton up and suck up are synonyms defined as:

cotton up and suck up: ingratiate oneself to; often with insincere behavior

Other synonyms of cotton up include cozy up, play up, shine up, sidle up.

cotton up (verb)	suck up (verb)
ingratiate oneself to; often with insincere behavior	try to gain favor by cringing or flattering
	take in, also metaphorically
	ingratiate oneself to; often with insincere behavior