suck up vs sidle up

suck up and sidle up both are verbs.

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

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

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

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

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