General Synonyms:
* Waver
* Dither
* Falter
* Pause
* Stumble
* Delay
* Procrastinate
* Vacillate
* Temperate
* Defer
* Reluctant
* Irresolute
* Doubtful
* Uncertain
* Indecisive
More Specific Synonyms:
* Back off (to withdraw from a commitment)
* Hold back (to restrain oneself)
* Be slow to (to be reluctant to do something)
* Think twice (to reconsider)
* Have second thoughts (to change one's mind)
The best synonym for "hesitate" will depend on the specific context of your sentence.