Entry 5 senses · 2 variants Webster, 1913 black out · IPA v. i. v. t. 01 v. i. to experience a temporary loss of consciousness, memory, or vision. 1. to experience a temporary loss of consciousness, memory, or vision. 02 v. t. to cause to become black, such as a stage, a computer screen, or a city. 1. to cause to become black, such as a stage, a computer screen, or a city. 2. to impose a blackout on (news or a sports event). 3. to make (a written text) illegible by applying a black ink over it; to blot out. 4. to suppress (a memory).