Contra and Underside

Contra noun - A member of the guerrilla force that opposed a left-wing government in Nicaragua.

Underside and contra are semantically related. in opposite topic. In some cases you can use "Underside" instead a noun "Contra".

Underside noun - The side or part facing downward from something.

Contra and underside are semantically related. Sometimes you can use "Contra" instead a noun "Underside".