1728 E. ChambersCycl.Decouple, in Heraldry, the same as Uncoupled, i. e. parted, or sever'd; Thus, a Chevron Decouple, is a Chevron wanting so much towards the Point, that the two Ends stand at a Distance from each other.
1830 in T. Robson Brit. Herald
This entry has not yet been fully updated (first published 1894; most recently modified version published online March 2018).