flannelmouth

[ flan-l-mouth ]
/ ˈflæn lˌmaʊθ /

noun, plural flan·nel·mouths [flan-l-mouth z] /ˈflæn lˌmaʊðz/.

a person whose speech is thick, slow, or halting.
a person whose speech is smoothly deceptive.

Origin of flannelmouth

An Americanism dating back to 1880–85; flannel + mouth
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019