nod vs drowse

nod and drowse both are nouns.

Word	Noun	Adjective	Verb	Adverb
nod	Yes	No	Yes	No
drowse	Yes	No	Yes	No

As verbs, drowse is a hypernym of nod; that is, drowse is a word with a broader meaning than nod:

nod (noun)	drowse (noun)
the act of nodding the head	a light fitful sleep
a sign of assent or salutation or command

nod (verb)	drowse (verb)
be almost asleep	be on the verge of sleeping
let the head fall forward through drowsiness	sleep lightly or for a short period of time
lower and raise the head, as to indicate assent or agreement or confirmation
express or signify by nodding
sway gently back and forth, as in a nodding motion