secondment vs agreement

secondment and agreement both are nouns.

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

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

secondment (noun)	agreement (noun)
the detachment of a person from their regular organization for temporary assignment elsewhere	compatibility of observations
a speech seconding a motion	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