The synonym of enough is sufficient, however, they are not interchangeable and mean slightly different in some cases.
Sufficient is the limit needed of something.
Enough might not be the limit but depending on the will or mood.
I have enough money to buy a house. - Here enough will mean I can buy the house and fulfill my other needs as well. Enough gives sense of fulfillment here. It indicates less towards the actual cost of the house, and more towards my sense of fulfillment.
I have sufficient money to buy the house. - Sufficient means that it does the job at present. Sufficient will always be relative to an imaginary amount, and it will imply that if my needs increase, I may not be in a comfortable position.