Brevis in longo
In Ancient Greek and Latin meter, brevis in longo (Classical Latin: [ˈbrɛwɪs ɪn ˈlɔŋgoː]) is a short syllable at the end of a line that is counted as long.
The term comes from Latin and means "a short [syllable] in place of a long [syllable]." Brevis in longo is possible in any classical meter that requires a long syllable at the end of a line, including dactylic hexameter and iambic trimeter.