recognize vs bob

recognize is not a noun while bob is a noun.

Word	Noun	Adjective	Verb	Adverb
recognize	No	No	Yes	No
bob	Yes	No	Yes	No

As verbs, bob is a hyponym of recognize; that is, bob is a word with a more specific, narrower meaning than recognize:

recognize: express greetings upon meeting someone
bob: make a curtsy; usually done only by girls and women; as a sign of respect

Other hyponyms of recognize include shake hands, curtsy, salute, present, salute, salute, hail, herald, receive, welcome, say farewell, bid, wish.

recognize (noun)	bob (noun)
	a short abrupt inclination (as of the head)
	a short or shortened tail of certain animals
	a small float usually made of cork; attached to a fishing line
	a hanging weight, especially a metal ball on a string
	a long racing sled (for 2 or more people) with a steering mechanism
	a hair style for women and children; a short haircut all around
	a former monetary unit in Great Britain

recognize (verb)	bob (verb)
perceive to be the same	cut hair in the style of a bob
be fully aware or cognizant of	make a curtsy; usually done only by girls and women; as a sign of respect
accept (someone) to be what is claimed or accept his power and authority	remove or shorten the tail of an animal
express obligation, thanks, or gratitude for	move up and down repeatedly in a quick, short movement
express greetings upon meeting someone	ride a bobsled
detect with the senses
grant credentials to
show approval or appreciation of
exhibit recognition for (an antigen or a substrate)