Pal·mer (pä?m?r, päl?-), Arnold 1929-2016. American golfer who was the first to win four Masters championships (1958, 1960, 1962, and 1964). American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.