1) Appendage 2) Extremity 3) Member 4) Swimmeret 1) Swimmeret 
• (n.) One of the abdominal legs of a crustacean. See Illust. under Crustacea.
Ple'o·pod noun ; plural English Pleopods , Latin Pleopoda . [ Greek ... to swim + -pod .] (Zoology) One of the abdominal legs of a crustacean. See Illust. under Crustacea . 
pleopod, pelopods 1. One of the abdominal legs of a crustacean. 2. One of the swimming limbs attached to the pleon or abdomen in Crustacea; also known as a swimmeret. A swimmeret is defined as an abdominal limb or appendage in many crustaceans, used in respiration and for carrying the eggs in females and usually adapted for swimming.