1. from alternative spelling of canvas (n.) and probably meaning, originally, "to toss or sift in a canvas sheet," hence "to shake out, examine carefully" (1520s); "to solicit votes" (1550s).
2. canvas => canvass => canvasser.
双语例句
1. Here was a type of the travelling canvasser for a manufacturing house -- a class which at that time was first being dubbed by the slang of the day " drummers.