cinched

adjective

Guaranteed to happen or be achieved; extremely easy to accomplish.

"The victory was cinched."

verb

Fastened or secured tightly with a strap or belt; made certain or guaranteed.

"She cinched her belt tightly."

Thesaurus

Synonyms: cinch, girth, pushover, picnic, walkover, snap, duck soup, breeze, child's play, piece of cake