To fulfill is to fill up, complete, accomplish, or carry something into effect. It may describe completing a task, satisfying a requirement, carrying out a word, or bringing a promised purpose to realization.
Scripture speaks of fulfilling the word of the Lord and frequently uses the term for the accomplishment of prophetic Scripture. Love is called the fulfillment of the law because it completely expresses what the law enjoins.
Older English usage sometimes means simply “to fill up” or “make full.” Revised translations may use “do,” “performed,” or “accomplished,” depending on the passage.