need vs necessitate

need is a noun but necessitate is not a noun.

Word	Noun	Adjective	Verb	Adverb
need	Yes	No	Yes	No
necessitate	No	No	Yes	No

As verbs, need and necessitate are synonyms defined as:

Other synonyms of need include ask, call for, demand, involve, postulate, require, take.

need (noun)	necessitate (noun)
the psychological feature that arouses an organism to action toward a desired goal; the reason for the action; that which gives purpose and direction to behavior
anything that is necessary but lacking
a condition requiring relief
a state of extreme poverty or destitution

need (verb)	necessitate (verb)
have need of	require as useful, just, or proper
have or feel a need for	cause to be a concomitant
require as useful, just, or proper