Frogging
Frogging means unraveling your knitting to fix a mistake or start over, named for the 'rip-it, rip-it' sound resembling a frog's croak.
Explanation
Frogging involves pulling the needle out of the stitches and pulling on the yarn so the knitting unravels, either because you've spotted a mistake further down or because you want to restart the project. The term is a pun on the sound of ripping out knitting resembling a frog saying 'rip-it, rip-it'. To avoid having to frog large portions of a project, it helps to count stitches regularly and consider placing a lifeline in tricky patterns, so you only need to frog back to the nearest safe point.