v. To humour; to induce the opposite effect of causing a person to become disgruntled.
the GNU version of the Collaborative International Dictionary of English
verb-intransitive. To grunt; to grunt repeatedly.
The Century Dictionary and Cyclopedia
To grunt.
To be sulky.
n. A grunting sound.
n. A snout.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
v. cause to be more favorably inclined; gain the good will of
Word Usage
"The OED and Merriam-Webster list that play on a word as a back-formation from disgruntle, and the word gruntle is born again—meaning “to put in a good humor.”"