Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
pestiferous is an adjective meaning "contaminated with infecting organisms". It carries 4 recorded senses.
likely to spread and cause an epidemic disease
“a pestilential malignancy in the air”
“plaguey fevers”
tending to corrupt or pervert
causing irritation or annoyance
“tapping an annoying rhythm on his glass with his fork”
“aircraft noise is particularly bothersome near the airport”
“found it galling to have to ask permission”
“an irritating delay”
“nettlesome paperwork”
“a pesky mosquito”
“swarms of pestering gnats”
“a plaguey newfangled safety catch”
“a teasing and persistent thought annoyed him”
“a vexatious child”
“it is vexing to have to admit you are wrong”
Definitions, synonyms and semantic relations for pestiferous come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.