Definition

A verbal stalling tactic used to buy thinking time in conversation—the awkward sound you make when your brain is buffering and your mouth is trying not to sit in silence.

Example Usage

When asked if I'd read the assignment, I just said, 'Err... well, most of it.'

Source: Urban Dictionary (https://www.urbandictionary.com/define.php?term=err...&defid=194232)