1.a fuck face half wit who knows fuck all about anything but thinks and acts like they do - this usualy leads to a fight where the "faggwam" in question gets the shit kicked out of them sideways.
2.just a general insult when nothing else cuts as a worthy insult.
3.or in the case of a case a female a "faggwamette".
guy1, hey that guys so stupid
guy2, yeah i know, what a "faggwam"