General synonyms:
* Delay
* Postponement
* Putting off
* Holding off
* Hesitation
* Indecision
* Laziness
* Slothfulness
* Dawdling
More formal synonyms:
* Deferment
* Remissness
* Dilatoriness
* Prevarication (implies deception or evasion)
More specific synonyms:
* Aversion to work: Apathy, inertia, indolence
* Fear of failure: Fear of commitment, perfectionism
* Lack of self-discipline: Disorganization, lack of motivation, impulsiveness
The best synonym will depend on the specific context and the meaning you want to convey.