The Collaborative International Dictionary of English v.0.48:

Mero \Me"ro\, n. [Sp.; cf. Pg. mero.]
   Any of several large groupers of warm seas, esp. the guasa
   (Epinephelus guaza), the red grouper (Epinephelus morio),
   the black grouper (Epinephelus nigritas), distinguished as