This is the 10613th most frequent Spanish word.
cumplir
To fulfill, to carry out, to comply, or to turn (age).
Here, 'cumplir' is used to describe fulfilling or keeping one's obligations or promises.
Yo siempre cumplo mis promesas.
I always keep my promises.
In this case, 'cumplir' is referring to the completion of a span of time.
El presidente cumplió cuatro años en el cargo.
The president completed four years in office.
Here, 'cumplir' indicates reaching a certain age.