nod vs motion

nod and motion both are nouns.

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

As nouns, motion is a hypernym of nod; that is, motion is a word with a broader meaning than nod:

nod: a sign of assent or salutation or command
motion: the use of movements (especially of the hands) to communicate familiar or prearranged signals

Other hypernyms of nod include gesture.

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

Other hypernyms of nod include gesticulate, gesture.

nod (noun)	motion (noun)
the act of nodding the head	a change of position that does not entail a change of location
a sign of assent or salutation or command	the act of changing location from one place to another
	the use of movements (especially of the hands) to communicate familiar or prearranged signals
	a formal proposal for action made to a deliberative assembly for discussion and vote
	a natural event that involves a change in the position or location of something
	an optical illusion of motion produced by viewing a rapid succession of still pictures of a moving object
	a state of change

nod (verb)	motion (verb)
be almost asleep	show, express or direct through movement
let the head fall forward through drowsiness
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