enmity - EHN-mih-TEE - mutual hatred, hostility, antipathy
Example: "A serious problem in the Mid Eastern countries is the tradition of enmity among their various religions."
As a starter: and as a former teacher in English, I hope to add to reader's vocabulary by presenting a word a day in simple terms that anyone can understand - from current use in publications, radio,TV, etc. Remember: use a new word three times in a day and it's yours forever!