Definition from Wiktionary, the free dictionary
butterflyfish (plural butterflyfishes or butterflyfish)
- Any of a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. Butterflyfish are fairly small, mostly from 12 to 22 cm (c.7-9 in) in length.
tropical marine fish