'keel over' definitions:

Definition of 'keel over'

From: WordNet
verb
Turn over and fall; "the man had a heart attack and keeled over"

Definition of 'keel over'

From: GCIDE
  • keel over \keel` o"ver\, v. i. To drop down in a faint, or as if dead; to die. [Colloq.] [PJC]

Synonyms of 'keel over'

From: Moby Thesaurus