-ee \-ee\ [Formed on the F. p. p. ending -['e], masc.]

A suffix used, chiefly in law terms, in a passive signification, to indicate the direct or indirect object of an action, or the one to whom an act is done or on whom a right is conferred; as in assignee, donee, alienee, grantee, etc. It is correlative to -or, the agent or doer.

Source: Webster's Revised Unabridged Dictionary (1913)