/tri mis"is/ , n. , pl. tremisses /-mis"eez/ .
1. Also called triens . a gold coin of the Eastern Roman Empire, the third part of a solidus, first issued in the 3rd century A.D.
2. a Merovingian gold coin imitating this.
[ 1700-10; tremissis, equiv. to L tre ( s ) THREE + -missis as in semissis, LL form of L semis SEMIS (falsely analyzed as se- + -missis ) ]