Webster's Revised Unabridged Dictionary · 1913

Muff

Muff (muf) , noun

[Compare LG. muff, Dutch mof, German, Danish, & Swedish muff, French moufle mitten, Late Latin muffula, Middle High German mouwe sleeve, Dutch mouw, and English muffle, v.]

1.
A soft cover of cylindrical form, usually of fur, worn by women to shield the hands from cold.
2.
(Mechanics) A short hollow cylinder surrounding an object, as a pipe.
3.
(Glass Manufacturing) A blown cylinder of glass which is afterward flattened out to make a sheet.
4.
A stupid fellow; a poor-spirited person. [Colloquial]
A muff of a curate. — Thackeray
5.
(Baseball) A failure to hold a ball when once in the hands.
6.
(Zoology) The whitethroat. [Provincial English]

Muff , transitive verb

To handle awkwardly; to fumble; to fail to hold, as a ball, in catching it.