For those unfamiliar, Johnson helpfully informs us that 'it's for your gooch, your Biffin's bridge, your perineum (the bit on your bum that after days in the saddle starts to chaffe).'
verb
(slang) To blunder or bungle; goof.
2017 Ansi, "Rise and Shine Sleepyhead", Welcome to the Wayne episode 1, 10 minutes
Olly, you gooched it! Fix it!