S / summissĭo
noun

summissĭo

gen. summissōnis · gender feminine · decl. 3rd
(), , summitto
a letting down; lowering; dropping
a letting down, lowering, dropping, sinking (Ciceron.): ex contentione vocis et summissione, Cic. Off. 1, 41, 146: (iterationes) erunt ab hac summissione orationis alienae, id. Or. 25, 85: nec elatio nec summissio, i. e. depression, id. Top. 18, 71.