Simple past tense and past participle of ally. (verb)
Joined as allies. (adjective)
Examples of word allied
Are there "natural experiments" in allied health professions?
U.S. companies need to be able to establish real partnerships (i.e. not just outsourcing) with industry in allied nations (sorry, this does NOT include adversaries like China or Russia) and compete on the open market.
The Army warned GIs away from "loose women" in allied as well as enemy nations.
After a series of negotiations with the British government, Hussein allied the Arabs with the British against the Turks.
In the "literary" camps of both SF and Fantasy, and in allied territories like slipstream and postmodernism, where experimentalist approaches are par for the course, we may well see logical impossibilities, outright self-contradictions, but for the most part the impossibilities we're dealing with are nomological.