Entomology. A haltere. Cf. poiser, n. 2. Obsolete.

Something which helps to preserve the balance; spec. the knobbed filaments (haltēres or poisers), which in two-winged flies replace the posterior…

A thing that poises or balances something; an organ used for balancing, spec. an insect's haltere.

Entomology. The pair of knobbed filaments, also called balancers and poisers, which in dipterous insects take the place of a pair of posterior wings.