look up any word, like fleek:
 
1.
One huge mutha of a lady sasquatch, often found in American all girl pop groups that change their line up regularly due to the Behemouth making the other girls appear to be dwarfs.
En Vogue and Destiny's Child removed the Behemouth beauties from their line up as the camera lens on the video couldn't fit their heads in.
by Gumbelley-Dickie December 24, 2011
 
2.
Anyone who favors incoherence, volume, or repetition over reason in an attempt to force outrageous lies on people, often in pursuit of a bastardized agenda. One who promotes and presents twisted truth as truth and spouts extremist bullcrap.

Anyone with a loud mouth.
The Fox News Channel is a haven for behemouths.

I wish that behemouth would just shut the hell up.
by Insufficient Postage April 25, 2006
 
3.
A large lady, usually muscular as opposed to fat, who will take advantage of any man that happens to be in her bed.

Also known as a Mammoth.
"I got attacked by a Behemouth last night"
by Joe DC January 15, 2007