slam dunk

(noun) something that is a sure to occur; a foregone conclusion. Synonyms: slam dunk. Example: "Predicting his success was a slam dunk."

(noun) a forceful dunk. Synonyms: slam dunk.

(verb) make a forceful move against. Synonyms: slam-dunk. Example: "The electronic travel market is slam-dunking traditional travel agencies."

(verb) make a slam dunk; shoot a basketball in a slam dunk. Synonyms: slam-dunk.