prearrangement vs agreement

prearrangement and agreement both are nouns.

Word	Noun	Adjective	Verb	Adverb
prearrangement	Yes	No	No	No
agreement	Yes	No	No	No

As nouns, agreement is a hypernym of prearrangement; that is, agreement is a word with a broader meaning than prearrangement:

Other hypernyms of prearrangement include arrangement.

prearrangement (noun)	agreement (noun)
something arranged in advance	compatibility of observations
	the thing arranged or agreed to
	the verbal act of agreeing
	the statement (oral or written) of an exchange of promises
	the determination of grammatical inflection on the basis of word relations
	harmony of people's opinions or actions or characters