Originally Posted by: BenoitI'd correct what I said a little with a dictionary definition :

sweep means laying your fingers in some part of the fretboard usually in the form of an arpeggio, then picking the notes of the arpeggio you have fingered, using either upstrokes or downstrokes continuously for all strings being played, while articulating each note in the pattern (unlike when strumming. This is usually achieved by removing each finger right after its corresponding note is played)