co·pal (k??p?l, -p?l?)n. Any of several brittle aromatic yellow to red resins of recent or fossil origin, obtained from various tropical trees and used in certain varnishes.[Spanish, from Nahuatl copalli, resin.]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.copal (?k??p?l; -pæl) n (Biochemistry) a hard aromatic resin, yellow, orange, or red in colour, obtained from various tropical trees and used in making varnishes and lacquers[C16: from Spanish, from Nahuatl copalli resin]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014co?pal (?ko? p?l, -pæl) n. a resin obtained from various tropical trees and used in making varnishes. [1570?80;