Source : Webster's Revised Unabridged Dictionary (1913)

Sweltry \Swel"try\, a. [See {Swelter}, {Swelt}, v. i., and cf.
   {Sultry}.]
   Suffocating with heat; oppressively hot; sultry. [R.]
   --Evelyn.

Source : WordNet®

sweltry
     adj : excessively hot and humid or marked by sweating and
           faintness; "a sweltering room"; "sweltering athletes"
           [syn: {sweltering}]