invitee (n.)

"solicit to come," 1530s, a back-formation from invitation, or else from French inviter (15c.), from Latin invitare "to invite," also "to summon, challenge; to feast, to entertain," a word of uncertain origin. Related: Invited; inviting.

word-forming element in legal English (and in imitation of it), representing the Anglo-French -é ending of past participles used as nouns (compare -y (3)). As these sometimes were coupled with agent nouns in -or, the two suffixes came to be used as a pair to denote the initiator and the recipient of an action.

Not to be confused with the French -ée that is a feminine noun ending (as in fiancée), which is from Latin -ata.