Definitions for: Three-cornered

[adj] involving a group or set of three; "a three-cornered race"
[adj] having three corners; "a three-cornered hat"

Webster (1913) Definition: Three"-cor`nered, a.
1. Having three corners, or angles; as, a three-cornered hat.

2. (Bot.) Having three prominent longitudinal angles; as, a
three-cornered stem.

Synonyms: angular, angulate, many-sided, multilateral