smothering vs choking

smothering is not a noun while choking is a noun.

Word	Noun	Adjective	Verb	Adverb
smothering	No	Yes	No	No
choking	Yes	Yes	No	No

As adjectives, smothering and choking are synonyms defined as:

smothering and choking: causing difficulty in breathing especially through lack of fresh air and presence of heat

Other synonyms of smothering include suffocating, suffocative.

smothering (noun)	choking (noun)
	the act of suffocating (someone) by constricting the windpipe
	a condition caused by blocking the airways to the lungs (as with food or swelling of the larynx)

smothering (adjective)	choking (adjective)
causing difficulty in breathing especially through lack of fresh air and presence of heat	causing difficulty in breathing especially through lack of fresh air and presence of heat