yawning vs opened

yawning is a noun but opened is not a noun.

Word	Noun	Adjective	Verb	Adverb
yawning	Yes	Yes	No	No
opened	No	Yes	No	No

yawning (noun)	opened (noun)
an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom

yawning (adjective)	opened (adjective)
showing lack of attention or boredom	used of mouth or eyes
gaping open as if threatening to engulf someone or something	made open or clear
with the mouth wide open indicating boredom or sleepiness	not sealed or having been unsealed