killer
adj. B2 Upper Intermediate US //ˈkɪɫɝ// UK //kˈɪlɐ// killer
adj. describing something that is very impressive, exciting, or difficult to beat. You use this when you think something is excellent or very effective.
adj. extremely effective, impressive, or formidable. In a sports or competitive context, it refers to a move or performance that is likely to secure a victory.
She has a killer serve that is impossible to return.
The striker scored a killer goal in the final minute to win the championship.
The team's killer instinct allowed them to capitalize on every minor defensive error made by their opponents during the second half.
From Middle English killer, kyller. By surface analysis, kill + -er.
Usage
Commonly used as an attributive adjective before the noun it modifies.