ring post; corner post
Specifically the padded post at the corner of a boxing or wrestling ring.
wasei-eigo (Japanese-coined English), from corner post
The boxer leaned against the corner post to rest.
corner flag; corner flagpost
In soccer, the flag and post marking the corner of the field. Often referred to as コーナーフラッグポスト.
See also: コーナーフラッグポスト
The player kept the ball near the corner flag.
Variant spelling with a middle dot; less common but still seen.
Wasei-eigo from English 'corner post'. The soccer sense is a shortening of コーナーフラッグポスト.