‖n.; pl. L. Pleurotomæ E. Pleurotomas [ NL., fr. Gr. &unr_; the side + tomh` a cut. ] (Zool.) Any marine gastropod belonging to Pleurotoma, and ether allied genera of the family Pleurotmidæ. The species are very numerous, especially in tropical seas. The outer lip has usually a posterior notch or slit. [ 1913 Webster ]