smiler vs pudding-face

smiler and pudding-face both are nouns.

Word	Noun	Adjective	Verb	Adverb
smiler	Yes	No	No	No
pudding-face	Yes	No	No	No

As nouns, pudding-face is a hyponym of smiler; that is, pudding-face is a word with a more specific, narrower meaning than smiler:

smiler: the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
pudding-face: a large fat human face

Other hyponyms of smiler include pudding face.

smiler (noun)	pudding-face (noun)
the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)	a large fat human face
a person who smiles