Webster’s Revised Unabridged Dictionary · 1913
Enorthotrope
En·or′tho·trope (ĕn·ôr′thō·trp), n. [Gr. ἐν in + ὀρθὸς upright, correct + τρέπειν to turn.] An optical toy; a card on which confused or imperfect figures are drawn, but which form to the eye regular figures when the card is rapidly revolved. See Thaumatrope.