From Longman Dictionary of Contemporary Englishmuffmuff1 /mʌf/ noun [countable] DCCa short tube of thick cloth or fur that you can put your hands into to keep them warm in cold weather → earmuffs
Examples from the Corpus
muff• It has a long snout, erect ears, a shiny brown coat, and a tail thick as a muff.• She held the lead in her gloved hands; behind her was Selene, with hers protected by a muff.• In the end, she and Bessie man-aged to make three of them into a muff and a little hat.• She carried a little fur muff.• Surreptitiously, her hand hidden within the furry confines of her muff, Anne made the sign of the cross.• She took off her muff and laid it down on the rough table made of planks and bricks.• I sometimes stimulate myself under my muff.• Mrs Kulass put on a ratty fur coat, a shabby felt hat, and put her hands inside an old muff.muffmuff2 verb [transitive] informal 1 (also muff something ↔ up)SPOIL 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 DSto 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→ See Verb tableExamples from the Corpus
muff• Clark muffed a routine groundball.• The waiter muffed the drink order.• They won't muff their lines or fall short in a crisis.Origin muff1 (1500-1600) Dutch mof, from Medieval Latin moffula “glove” 