1. respond angrily or rudely to somebody
I was just trying to help, you don't need to bite my head off!
When someone loses their temper and shouts at someone, they are said to be biting that person's head off, almost like an animal snapping at their face! This is usually used when such a reaction occurs without apparent reason or is seen as a disproportionate response to the circumstances. If you 'bite someone's head off', you are probably very angry with them or the situation in which you find yourself. Similar in meaning to 'snap at' someone. You can use this expression in any context, social or professional but it is used more often in informal contexts.