The Collaborative International Dictionary of English v.0.48:
Worshiper \Wor"ship*er\, n. One who worships; one who pays divine honors to any being or thing; one who adores. [Written also worshipper.] [1913 Webster]WordNet (r) 3.0 (2006):
worshiper n 1: someone who admires too much to recognize faults [syn: worshiper, worshipper] 2: a person who has religious faith [syn: believer, worshiper, worshipper]