doctor-fish

from The Century Dictionary.

• noun A fish of the genus Acanthurus: so called from the sharp and glassy, lancet-like, movable spines with which it is armed on each side of the tail, so that it cannot be handled incautiously with impunity. All the species belong to the tropics. Also called doctor, surgeon, surgeon-fish, barber-fish.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun surgeon fish of the West Indies