nys·tag·mus 
(nĭ-stăgməs)
(nĭ-stăgməs)n.
A rapid, involuntary, oscillatory motion of the eyeball.
[New Latin, from Greek nustagmos, drowsiness.]
nys·tagmic (-mĭk) adj.
- instigation
- instigative
- instigator
- instil
- instill
- instillation
- instiller
- instillment
- instinct
- instinctive
- instinctively
- instinctual
- instinctually
- in stitches
- institute
- instituter
- institution
- institutional
- institutionalism
- institutionalist
- institutionalization
- institutionalize
- institutionally
- institutor
- in stock