The Collaborative International Dictionary of English v.0.48:
Tic \Tic\, n. [F.] (Med.) A local and habitual convulsive motion of certain muscles; especially, such a motion of some of the muscles of the face; twitching; velication; -- called also spasmodic tic. --Dunglison. [1913 Webster] Tic douloureux. [F., fr. tic a knack, a twitching + douloureux painful.] (Med.) Neuralgia in the face; face ague. See under Face. [1913 Webster]