na-adjective, noun which may take the genitive case particle 'no'
exact opposite; polar opposite
Emphasizes a complete reversal or diametrical opposition. Often used in casual speech and writing.
His opinion is the exact opposite of mine.
I ended up going in the completely opposite direction.
Compound of 真 (ma, 'true') + 逆 (gyaku, 'opposite'). The reading まぎゃく is a straightforward combination of the two components.