Oppugnant is an adjective that means opposing or antagonistic.

Having been around since the early 16th century, our word of the day comes from the Latin verb oppugnare (oh pug NAR ay) which means ‘to oppose.’ oppugnant can be used in nearly any context where someone or something opposes us. 

The oppugnant students may not have liked my idea of implementing a school uniform, but I felt we needed some discipline in that place. Not many people agreed with me. The opposing forces would win that debate.