suck vs fellate

suck is a noun but fellate is not a noun.

Word	Noun	Adjective	Verb	Adverb
suck	Yes	No	Yes	No
fellate	No	No	Yes	No

As verbs, suck and fellate are synonyms defined as:

Other synonyms of suck include blow, go down on.

suck (noun)	fellate (noun)
the act of sucking

suck (verb)	fellate (verb)
give suck to	provide sexual gratification through oral stimulation
draw into the mouth by creating a practical vacuum in the mouth
take in, also metaphorically
draw something in by or as if by a vacuum
provide sexual gratification through oral stimulation
be inadequate or objectionable
attract by using an inexorable force, inducement, etc.