I. muff 1 /mʌf/ BrE AmE noun [countable]
[ Date: 1500-1600 ; Language: Dutch ; Origin: mof , from Medieval Latin moffula 'glove' ]
a short tube of thick cloth or fur that you can put your hands into to keep them warm in cold weather ⇨ earmuffs
II. muff 2 BrE AmE verb [transitive] informal
1 . ( also muff something ↔ up ) to spoil a chance to do something well or achieve something:
You’ll probably only get one chance to take a photo, so don’t muff it!
2 . to fail to catch a ball or kick it properly in a game or sport:
With only the goalkeeper to beat, he completely muffed his shot.
3 . muff your lines British English if you muff your lines in a play you are acting in, you forget them or say them wrongly