Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
sultriness is a noun meaning "oppressively hot and humid weather". It carries 2 recorded senses.
oppressively hot and humid weather
the quality of expressing or arousing sexual desire
“the sultriness of her look was unmistakable”
“the sultriness of lust was in the air”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for sultriness come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.