disgruntle (v.)

"disappoint, offend, throw into a state of sulky dissatisfaction," 1680s, from dis-, here probably meaning "entirely, very," + obsolete gruntle "to grumble, utter a low grunt" (Middle English gruntelen, early 15c.), frequentative of grunt (v.); hence "to complain" (by 1560s). All citations in OED are in the form of the past-participle adjective.