means Something or someone positioned as far as possible from another in nature, direction, or position — the contrary or reverse of it.

from From Latin oppositus, the past participle of opponere, 'to set against' — ob- ('against') welded to ponere ('to place'). So an opposite is literally something placed against you, planted face-to-face across the divide. It traveled through Old French into English in the 14th century, keeping that sense of two things squared off and staring each other down.