adjective [ usually before noun ]
1.
having three corners :
a three-cornered hat
2.
involving three people or groups :
a three-cornered contest
adjective [ usually before noun ]
1.
having three corners :
a three-cornered hat
2.
involving three people or groups :
a three-cornered contest
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005