gesture vs bow down

gesture is a noun but bow down is not a noun.

Word	Noun	Adjective	Verb	Adverb
gesture	Yes	No	Yes	No
bow down	No	No	Yes	No

As verbs, bow down is a hyponym of gesture; that is, bow down is a word with a more specific, narrower meaning than gesture:

gesture (noun)	bow down (noun)
motion of hands or body to emphasize or help to express a thought or feeling
something done as an indication of intention
the use of movements (especially of the hands) to communicate familiar or prearranged signals

gesture (verb)	bow down (verb)
show, express or direct through movement	bend one's knee or body, or lower one's head
	get into a prostrate position, as in submission