-arsuff. Of, relating to, or resembling: polar.[Middle English, from Old French -er, from Latin -?ris, variant of -?lis, -al.]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.-ar suffix forming adjectives of; belonging to; like: linear; polar; minuscular. [via Old French -er from Latin -?ris, replacing -?lis (-al1) after stems ending in l]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ar- var. of ad- before r: arrear. -ar1 , var. of -al1, joined to words in which an l precedes the suffix: circular; lunar; singular. [