terce/tɜːs/EtymologyLate Middle English, from Old French terce, from Latin tertia (“third; the third hour”).terce means The third hour of daylight (about 9 am). Lexicurio rates it Sui generis — a strength score of 89 out of 100.nounThe third hour of daylight (about 9 am).The service appointed for this hour.A widow's right, where she has no conventional provision, to a liferent of a third of the husband's heritable property.