To unravel a hand knitted or crocheted fabric, either partially or entirely. Frogging is usually accomplished by taking the needles out of the project and pulling on the working yarn which drops out of the series of loops that make the fabric. The term originates with the similarity between RIP IT (unravel) and RIBBIT (the sound a frog makes).
See also TINK
After I finished the sweater, the stupid thing looked horrible on me, so I frogged it.
To undo knitting one stitch at a time. Tink is Knit backwards. A slower, more precise version of FROG
I found a mistake in my knitting and tinked back to fix it.