contra
mid-14c., from Latin contra (prep. and adv.) "against," originally "in comparison with," ablative singular feminine of *com-teros, from Old Latin com "with, together" (see com-) + -tr, zero degree of the comparative suffix -ter-.
Contra (n.)
1981, "anti-Sandinista Nicaraguan," short for Spanish contrarrevolucionario "counter-revolutionary."