From head + off.
head off (third-person singular simple present heads off, present participle heading off, simple past and past participle headed off)
- (intransitive) To begin moving away.
- (We will head off on our holidays tomorrow)
- (transitive) To intercept.
- The cavalry will head off the bandits at the pass.
- (transitive) To avoid some usually negative consequence.
- The government took steps to head off summertime shortages of gasoline.
to avoid a negative consequence