Refers to the frothing of the mouth often comically representative of eagerness and desperation. It's used to describe an overly desperate or needy person (both male or female) in a dating situation.
A man and a woman hooked up once, exchanged numbers, and part ways. the woman calls or texts all the time, asking for a date or another hook up - constantly offering herself on a silver plate. She is a frother.
Similar to a brother from another mother however, a Frother is considered to be a level higher, a friendship where the participants can now anticipate the others activities that they might aswell be a brother. Like blood brother but avoiding the transmittance of any blood borne disease.
"What is up my Frother!"
"If you don't get off my porch my Frother will kick your ass"
"I just Frothered Jeff"
Next seasons BBC Drama " Band of Frothers - Return of the Reich"