From Longman Dictionary of Contemporary Englishpestilentialpes‧ti‧len‧tial /ˌpestəˈlenʃəl◂/ (also pestilent /ˈpestələnt/) adjective 1 literaryUNPLEASANT extremely unpleasant and annoying2 old useMI causing disease
Examples from the Corpus
pestilential• They squeezed across the narrow bridge ten abreast - one hideous, brown, pestilential beast with a hundred buckling legs.• pestilential disease• pestilential kids• Good job too, a young thing like her oughtn't to be out late on a pestilential night like this. 