Merriam-Webster Dictionary:
* To carry out completely; to bring to a successful end; *fulfill a contract*
* To bring about the realization of; *fulfill a promise*
* To meet the requirements of; *fulfill a need*
* To satisfy or meet the needs of; *fulfill a duty*
* To achieve, reach, or attain; *fulfill a destiny*
Oxford English Dictionary:
* Carry out, achieve, or fulfill (something promised, expected, or desired)
* Satisfy (a requirement or condition)
* Meet the requirements of (a role, purpose, etc.)
Cambridge Dictionary:
* To do something that is expected, promised, or necessary
* To achieve something that you hoped for or intended to do
* To make something complete
Dictionary.com:
* To bring to completion or fulfillment: *fulfill a promise*
* To carry out or perform (a duty, obligation, etc.)
* To satisfy or meet the needs of
* To achieve (a goal, purpose, etc.)
In essence, "fulfill" means to complete, achieve, or satisfy something that is expected, promised, or desired. It implies the successful completion of a task, obligation, or goal.