It's a misspelling. It should be "canvass" (with two s-es).
meaning: question (someone) in order to ascertain their opinion:
examples: they promised to canvass all member clubs for their views."
New Oxford American Dictionary
meaning 1
1 [with object] solicit votes from (electors in a constituency): in each ward, two workers canvassed some 2,000 voters | [no object] : she canvassed for votes.
• try to obtain; request: they're canvassing support among shareholders.
• question (someone) in order to ascertain their opinion: they promised to canvass all member clubs for their views.