One who brownnoses (flatters or humors somebody in an obsequious manner for personal gain); one who sucks up; a bootlicker, ass-kisser, sycophant.
One who idles; a lazy person; a sluggard.
One who idles; one who spends his or her time in inaction.
A mechanical device such as a pulley or wheel that does not transmit power, but supports a moving belt etc.