filatory UK /ˈfɪlətəɹi/US /ˈfɪləˌtɔɹi/ noun1 •(no longer used) A machine for forming threads.It [a silk manufactory] has 3 filatories, each of 640 reels, which are set in motion by a water-wheel; and besides a small filatory, turned by men. — 1799 formsfilatories