pull a face vs smile

pull a face is not a noun while smile is a noun.

Word	Noun	Adjective	Verb	Adverb
pull a face	No	No	Yes	No
smile	Yes	No	Yes	No

As verbs, smile is a hyponym of pull a face; that is, smile is a word with a more specific, narrower meaning than pull a face:

pull a face: contort the face to indicate a certain mental or emotional state
smile: change one's facial expression by spreading the lips, often to signal pleasure

Other hyponyms of pull a face include squinch, squint, wince, frown, glower, lour, lower, screw up, mop, mow, pout.

pull a face (noun)	smile (noun)
	a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement

pull a face (verb)	smile (verb)
contort the face to indicate a certain mental or emotional state	change one's facial expression by spreading the lips, often to signal pleasure
	express with a smile