my·o·to·ni·a 
(mī′ə-tōnē-ə)
(mī′ə-tōnē-ə)n.
Tonic spasm or temporary rigidity of one or more muscles, often characteristic of various muscular disorders.
my′o·tonic (-tŏnĭk) adj.
- unpleasant
- unpleasantly
- unpleasantness
- unpleasantry
- unplug
- unplugged
- unplumbed
- unpolished
- unpolitical
- unpopular
- unpopularity
- unpracticed
- unprecedented
- unprecedentedly
- unpredictability
- unpredictable
- unpredictably
- unprejudiced
- unpremeditated
- unprepared
- unpreparedly
- unpreparedness
- unprepossessing
- unpretending
- unpretentious