Inimical is an adjective that means indicating hostility.

Our word of the day has its roots in the Latin word amicus (ah ME coos) which means ‘friend.’ By adding the negative prefix I-N, we get a word for someone not behaving in a friendly manner. Inimical behavior is considered adversarial or antagonistic.

I didn’t understand Charlie’s inimical feelings for his neighbor Jen until I learned about the incident involving Jen’s doberman. After hearing about that dog’s history I instantly understood his adversarial feelings.