diplomacy vs negotiation

diplomacy and negotiation both are nouns.

Word	Noun	Adjective	Verb	Adverb
diplomacy	Yes	No	No	No
negotiation	Yes	No	No	No

As nouns, negotiation is a hypernym of diplomacy; that is, negotiation is a word with a broader meaning than diplomacy:

Other hypernyms of diplomacy include dialogue, talks.

diplomacy (noun)	negotiation (noun)
subtly skillful handling of a situation	the activity or business of negotiating an agreement; coming to terms
wisdom in the management of public affairs	a discussion intended to produce an agreement
negotiation between nations