The comparative (or even superlative) form of the adjective vehement, accented on the second syllable. Used as an intensifier, often in especially eloquent barroom discussions after several rounds. Example: Hey! Calm down. I didn't mean anything by it. You don't have to get all vehemenent about it.
VEHEMENENT
Meaning of VEHEMENENT in English
Slang English vocab. Английский сленговый словарь. 2012