n.; pl.Telsons [ NL., fr. Gr. &unr_; a boundary, limit. ] (Zool.) The terminal joint or movable piece at the end of the abdomen of Crustacea and other articulates. See Thoracostraca. [ 1913 Webster ]
(n) any of several minute primitive wingless and eyeless insects having a cone-shaped head; inhabit damp soil or decaying organic matter, Syn. telsontail