moving off on a tangent..

frog is also a 'verb'

when a mistake has been discovered several row back in a work of knitting, its common to take the work off the needles and rip it. (rip it, rip it, "riv it".--or more commonly, to frog (in the US frogs say "riv it')

(to undo a few stitches (for a mistake found before the row is completed it to tink (knit backwards)