Entry 3 senses · 2 variants Webster, 1913 Killing /kĭl'-ĭng/ · Kill·ing · IPA /ˈkɪl.ɪŋ/ a. n. 01 a. Literally, that kills; having power to kill; fatal; in a colloquial sense, conquering; captivating; irresistible. 1. Literally, that kills; having power to kill; fatal; in a colloquial sense, conquering; captivating; irresistible. “Those eyes are made so killing.” — Pope. “Nothing could be more killingly spoken.” — Milton. 02 n. The act or process of causing a living organism to die. 1. The act or process of causing a living organism to die. 2. An unusually large gain in a financial or business transaction or enterprise; as, she made a killing trading cattle futures.