Archaic indicator of one who regularly indulges in black market attention enhancing substances most often the vast umbrella encompassing what in the vernacular is referanced as speed.
Also a bad ass heavy metal band known to have influenced many far more monitarily successful bands.
Person1: Why is Tina digging a hole in her backyard?
Person 2: She's a moterhead, she's ben awake for 4 days. Her Motethead albums told her to hide her entire vinyl collection before the feds arrive in black Hellacopters. They might collect them as evidence against her illeagal ice distribution ring.