noun, na-adjective, noun which may take the genitive case particle 'no'
absolutely accurate; unmatched precision
Emphatic compound meaning accuracy that is peerless or flawless. Often used in formal or technical descriptions.
彼の射撃は正確無比だ。
His shooting is absolutely accurate.
この機械は正確無比な測定を提供する。
This machine provides measurements of unmatched precision.
正確 means 'accurate' or 'precise' in a general sense. 正確無比 adds the element of being peerless or incomparable, making it a stronger, more emphatic expression.
Compound of 正確 (accurate) and 無比 (unparalleled, peerless). The combination creates an emphatic term for flawless accuracy.