Comparative form of sultry: more sultry(adjective)
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Use "sultrier" in a sentence
"With her voice stretched from smoky and sultry to smokier and sultrier, too many of them lumber along with the pace of a pallbearer."
"From Reebok to Nike to the Addidas -- whose recent collaboration with Stella McCartney has yielded a string of racy pieces -- clothes are getting sleeker and sultrier."
"She worked towards pulling off something a little sultrier than usual, but her walk was unconvincing."