Origin: Latin suffix -ment
Fulfillment has 3 different meanings across 1 category:
a feeling of satisfaction at having achieved your desires
"After years of hard work, she finally found true fulfillment when her novel was published and readers began praising it."
the act of consummating something (a desire or promise etc)
"The couple finally achieved a deep sense of fulfillment after years of waiting when they were able to consummate their marriage."
Alternative form of fulfilment
"The dictionary notes that fulfillment is an alternative spelling of fulfilment, so both forms are acceptable in British English usage."
In plain English: Fulfillment is the feeling of satisfaction you get when you finally achieve something important to you.
"She found great fulfillment in helping her community during the charity drive."