Canvasser (noun)

A person who seeks support or votes, especially by going door to door, or a person who sells goods or services by visiting people's homes.

Origin:

Late middle english: from old french canvasser, from canevas piece of canvas, from latin cannabaceus made of hemp.

Examples:

1. The canvasser was collecting signatures for a petition.
2. The canvasser was trying to drum up support for the candidate.
3. The canvasser was offering a free trial of a new product.
4. The canvasser was conducting a survey of local residents.
5. The canvasser was asking for donations for a charity.