MUFFING
Etymology
In the sexual sense, popularized by Mira Bellwether's 2010 zine "Fucking Trans Women".
Verb
muffing
present participle of muff
Noun
muffing (uncountable)
(slang) Penetration of the inguinal canal (e.g. with a finger, or by pushing the testicle back inside it) as a form of sexual activity among trans women.
Source: Wiktionary
MUFF
Muff, n. Etym: [Cf. LG. muff, D. mof, G., Dan., & Sw. muff, F. moufle
mitten, LL. muffula, MHG. mouwe sleeve, D. mouw, and E. muffle, v.]
1. A soft cover of cylindrical form, usually of fur, worn by women to
shield the hands from cold.
2. (Mech.)
Definition: A short hollow cylinder surrounding an object, as a pipe.
3. (Glass Manuf.)
Definition: A blown cylinder of glass which is afterward flattened out to
make a sheet.
4. Etym: [Perhaps a different word; cf. Prov. E. maffle to slammer.]
Definition: A stupid fellow; a poor-spirited person. [Colloq.] "A muff of a
curate." Thackeray.
5. Etym: [See 4.] (Baseball)
Definition: A failure to hold a ball when once in the hands.
6. (Zoöl.)
Definition: The whitethroat. [Prov. Eng.]
Muff, v. t. [imp. & p. p. Muffed; p. pr. & vb. n. Muffing.]
Definition: To handle awkwardly; to fumble; to fail to hold, as a ball, in
catching it.
Source: Webster’s Unabridged Dictionary 1913 Edition