Soporiferous means inducing sleep, from Latin sopor, deep sleep, plus -fer, bearing — on record since 1583, and mostly displaced since by the shorter soporific. It opens a week A.Word.A.Day calls “words with scene-stealing examples”, and the example steals it: Angela Huth’s Spectator diary of a grey-haired visiting preacher whose soporiferous sermon lulled a congregation of six elderly ladies into instant lethargy — until she shrieked “and God went WOW!”, twice, and incomprehension skittered along the pews.