Medical Definition of flat
1: being or characterized by a horizontal line or tracing without peaks or depressions <the EEG is ominously flat indicating that her brain function is gone—Don Gold>
2: characterized by general impoverishment in the presence of emotion-evoking stimuli <flat affect often occurs in schizophrenia>
Learn More about flat
Seen and Heard
What made you want to look up flat? Please tell us where you read or heard it (including the quote, if possible).