cut·lass also cut·las (k?t?l?s)n.1. A short heavy sword with a curved single-edged blade, once used as a weapon by sailors.2. Caribbean A machete.[French coutelas, from Old French coutelasse, probably augmentative of coutel, knife, from Latin cultellus, diminutive of culter, knife; see skel- in Indo-European roots.]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.cutlass (?k?tl?s) n (Arms & Armour (excluding Firearms)) a curved, one-edged sword formerly used by sailors[C16: from French coutelas, from coutel knife, from Latin cultellus a small knife, from culter knife; see coulter]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014cut?lass or cut?las (?k?t l?s) n. a short, curving sword with a single cutting edge, formerly used by sailors. [1585?95; earlier coutelace