Definite (adjective) or definitely (adverb) means certain, without a single doubt:

We have definite plans to move to New York.

(it is 100% certain that we will move there)

I'm definitely going to the party.

(it is 100% certain that I am going)

This $50 jacket is definitely overpriced. I saw the exact same jacket for $30 in another store.

(it is completely certain that $50 is too much)

The word definitively (adverb) or definitive (adjective) means that something decides an issue, or provides a clear and firm answer/solution to a particular matter:

The evidence from the DNA test definitively proved that Ryan was not the murderer.

The company had been in financial trouble for years, but its definitive end came when it declared bankruptcy in March.

Carrer Success Tips

Measure Your Own Success

How do you define success, Is it the size of your paycheck or having the corner office, Is it the feeling you get when you know you did a great job on a project (praise from the boss doesnt hurt) or the one you get when you know you helped someone, Perhaps you feel successful after putting in a day at work and coming home at a reasonable hour to spend time with your family. Since everyone measures success differently, only you can determine what it means to you. Your satisfaction with your career is strongly linked to how successfully you feel you have met your own, and not anyone elses, definition of it.