noun which may take the genitive case particle 'no', na-adjective, noun
equal; evenly matched; on par
Describes two parties, abilities, or forces that are closely matched, with no clear advantage. Often used in competitive contexts such as sports, games, or debates.
両チームの実力は互角だ。
The two teams are evenly matched in ability.
彼はプロと互角に戦える。
He can compete on equal terms with professionals.
The kanji 互 (mutual) and 角 (horn/angle) combine to suggest two horns locking evenly, hence 'equal in strength'. The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning.