negotiatress vs negotiator

negotiatress and negotiator both are nouns.

Word	Noun	Adjective	Verb	Adverb
negotiatress	Yes	No	No	No
negotiator	Yes	No	No	No

As nouns, negotiator is a hypernym of negotiatress; that is, negotiator is a word with a broader meaning than negotiatress:

negotiatress: a woman negotiator
negotiator: someone who negotiates (confers with others in order to reach a settlement)

Other hypernyms of negotiatress include negotiant, treater.

negotiatress (noun)	negotiator (noun)
a woman negotiator	someone who negotiates (confers with others in order to reach a settlement)