Definition of "obverse"

Turned or facing toward the observer.  examples

Corresponding; complementary.  examples

(botany) Having the base, or end next to the attachment, narrower than the top.  examples

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

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