What is the meaning of Obverse?

Turned or facing toward the observer.

Corresponding; complementary.

Having the base, or end next to the attachment, narrower than the top.

The heads side of a coin, or the side of a medal or badge that has the principal design.

A proposition obtained by obversion, e.g. All men are mortal => No man is immortal.

vocative masculine singular of obversus

Source: wiktionary.org