poller

Noun

 * 1) one who polls or lops trees
 * 2) one who cuts hair; a barber
 * 3) one who votes
 * 4) one who registers voters or conducts a poll
 * 5)  a task or process that periodically checks for a condition being satisfied, such as the availability of new data

Noun

 * 1) a retractable road bollard