|Noah Webster's Dictionary|
1. (superl.) Very hot, burning, and oppressive; as, Libya's sultry deserts.
2. (superl.) Very hot and moist, or hot, close, stagnant, and oppressive, as air.
Sultry (1 Occurrence)
Jonah 4:8 It happened, when the sun arose, that God prepared a sultry east wind; and the sun beat on Jonah's head, so that he fainted, and requested for himself that he might die, and said, "It is better for me to die than to live." (WEB ASV DBY RSV)