1) To kill someone gruesomely.
2) Originates from the movie/musical known as 'Sweeney Todd'. In this movie, Johnny Depp plays the role of Sweeney Todd, a barber that slits peoples throat while giving them a shave.
3) To Sweeney todd someone, you would have to kill them in the same manner as Sweeney Todd himself of an alternative way that is just as horrific.
To arrive at an Audio-Visual setup and find the driver as the lead contact for your set-up crew. Normally associated with a fucked-up situation that predicts a series of unfortunate events that will negatively impact your mental health.