Webster's Revised Unabridged Dictionary · 1913

Killing

Killing , adjective

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

killing , noun

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.