c. 1300 (late 12c. as a surname), polle, "hair of the head; piece of fur from the head of an animal," also (early 14c.) "head of a person or animal," from or related to Middle Low German or Middle Dutch pol "head, top." The sense was extended by mid-14c. to "person, individual" (by polls "one by one," of sheep, etc., is recorded from mid-14c.)
Meaning "collection or counting of votes" is recorded by 1620s, from the notion of "counting heads;" the sense of "the voting at an election" is by 1832. The meaning "survey of public opinion" is recorded by 1902. A poll tax, literally "head tax," is from 1690s. Literal use in English tends toward the part of the head where the hair grows.
1620s, "to take the votes of," from poll (n.) in the extended sense of "individual, person," on the notion of "enumerate one by one." Sense of "receive (a certain number of votes) at the polls" is by 1846. Related: Polled; polling. Polling place is attested by 1832.
"to cut, trim, remove the top of," early 14c., pollen, "to cut short the hair" (of an animal or person), from poll (n.). Of trees or plants from mid-15c. (implied in polled), Related: Polling. A deed poll "deed executed by one party only," is from the earlier verbal meaning "cut the hair of," because the deed was cut straight rather than indented (compare indenture (n.)).