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.
(Synonym: habit spasm). Habitual movements which may range from sniffing to throat clearing to grimacing, etc. which are incessantly repeated in situations in which they are not called for (or even appropriate). The affected individual may or may not be aware of them -- and may or may not be able to consciously control them.
An involuntary, sudden, rapid, recurrent, nonrhythmic, stereotyped motor movement or vocalization.