'Killingly' definitions:

Definition of 'killingly'

(from WordNet)
adverb
In a very humorous manner [syn: killingly, sidesplittingly]

Definition of 'Killingly'

From: GCIDE
  • Killing \Kill"ing\, a. Literally, that kills; having power to kill; fatal; in a colloquial sense, conquering; captivating; irresistible. -- {Kill"ing*ly}, adv. [1913 Webster]
  • Those eyes are made so killing. --Pope. [1913 Webster]
  • Nothing could be more killingly spoken. --Milton. [1913 Webster]