Definition of telson in US English:



  • The last segment in the abdomen, or a terminal appendage to it, in crustaceans, chelicerates, and embryonic insects.

    • ‘At the end of the abdomen is the telson, which bears a bulb-shaped structure containing the venom glands and a sharp, curved aculeus to deliver the venom.’
    • ‘The material comprises several partial specimens in addition to disarticulated carapaces, appendages, metastomas, opisthosomal segments, and telsons.’
    • ‘The postabdominal series is entire in this specimen, exhibiting a total count of nine segments plus the telson.’
    • ‘In a similar way, setiferous appendages of the telson are found in a number of noncrustaceans.’
    • ‘They have a long, spike-like appendage called a telson that projects from the rear of their bodies.’


Mid 19th century: from Greek, literally ‘limit’.