muff¹ / məf/ • n. 1. a tube made of fur or other warm material into which the hands are placed for warmth. ∎  a warm or protective covering for other parts of the body.2. vulgar slang a woman's genitals.muff² inf. • v. [tr.] handle (a situation, task, or opportunity) clumsily or badly: the administration muffed several of its biggest projects. ∎  fail to catch or receive (a ball) or to hit (a shot or a target): the catcher muffed a perfect throw home. ∎  speak (lines from a theatrical part) badly: he was starting to muff his lines.• n. a mistake or failure, esp. a failure to catch or receive a ball cleanly.

muff1 cylindrical covering for the hands. XVI. — Du. mof, shortening of MDu. moffel, muffel (corr. to F. moufle) — medL. muff(u)la, of unkn. orig.

muff2 awkward person at sport, (gen.) duffer. XIX. of unkn. orig.
Hence vb. make a muddle OF. XIX.