telson

The rearmost segment of the body of certain arthropods.

An extension of this segment, such as the middle lobe of the tail of a lobster or the stinger of a scorpion.

In zoology, the last segment, or an azygous appendage of the last segment, or the median axis of the last segment, whether in one piece or more, of certain crustaceans and arachmidans, as the middle flipper of a lobster’s tail-fin, the long sharp tail of a horseshoe-crab, and the sting of a scorpion.

The terminal joint or movable piece at the end of the abdomen of Crustacea and other articulates. See thoracostraca.

The part of an arthropod posterior to the last segment.