WordNet sense 1 (an inquiry into public opinion conducted by interviewing a random sample of people):

canvass, opinion poll, public opinion poll

WordNet sense 2 (the top of the head):

crown, pate, pate

WordNet sense 3 (get the opinions (of people) by asking specific questions):

canvas

WordNet sense 4 (a tame parrot):

poll parrot

WordNet sense 5 (convert into a pollard):

pollard