Definition of hippus in US English:

hippus

noun

Medicine
  • Spasmodic or rhythmic contraction of the pupil of the eye, a symptom of some neurological conditions.

    • ‘Even a pronounced hippus may be physiological and does not necessarily require extensive diagnostic investigations.’
    tightening, tensing, flexing, constricting
    View synonyms

Origin

Late 17th century: modern Latin, from Greek hippos ‘tremor of the eyes’.

Pronunciation

hippus

/ˈhipəs/