Truncate

Definition

Abruptly cut off or appearing to end as if by a transverse cut; describing a structure with a squared-off, flattened, or non-tapering distal margin rather than a pointed or rounded termination.

Etymology

Latin truncare, to cut off, maim

Example

The elytra of some ground beetles (Carabidae) are truncate, exposing one or more abdominal tergites; truncate wing tips in certain Diptera lack the pointed apex typical of related species.

Synonyms

• truncated

Related Terms

• Emarginate
• obtuse
• apex
• Distal
• attenuate

Usage Notes

In morphological descriptions, truncate is absolute—applied when the terminal margin is essentially flat and perpendicular to the long axis—versus merely short or reduced. Contrast with rounded, acuminate, or caudate (tapering to a point). Often qualified as 'broadly truncate' or 'narrowly truncate' to indicate relative width of the terminal margin.