cercus

< /ˈsɜr saɪ, ˈkɛr ki/.

1. one of a pair of appendages at the rear of the abdomen of certain insects and other arthropods, serving as tactile organs.

noun plural -ci (-siː)

1. one of a pair of sensory appendages at the tip of the abdomen of some insects and other arthropods

n. pl. cer•ci (sûr′sī, -kī)

1. A stiff hairlike structure.
2. Either of a pair of terminal, dorsolateral sensory appendages of certain insects, such as the female mosquito.