An Etymological Dictionary of Astronomy and Astrophysics

Subject to the weather that is hot and dry enough to scorch land.

Etymology (EN): From L. torridus “dried with heat, scorching hot,” from torrere “to dry up, roast,” related to terra “earth,” literally “dry land;” from PIE base *ters- “to dry” (cf. Pers. tešné “thirsty;” Mid.Pers. tašnak “thirsty;” Av. taršu- “dry,” taršna- “thirst;” Skt. trsta- “dry,” tars- “to be thirsty;”
Gk. teresesthai “to become or be dry;” Goth. þaursus “dry, barren,” O.H.G. derren “to make dry,” durst “thirst;” Ger. dürr “arid;” O.E. þurstig “thirsty”).

Etymology (PE): Tafsân, tafsâ, from tafsidan “to become hot,” variants tâftan, tâbidan “to shine;”
Mid.Pers. tâftan “to heat, burn, shine;” taftan “to become hot;” Parthian t’b “to shine;”
Av. tāp-, taf- “to warm up, heat,” tafsat “became hot,” tāpaiieiti “to create warmth;” cf. Skt. tap- “; to heat, be/become hot; to spoil, injure, damage; to suffer,” tapati “burns;” L. tepere “to be warm,” tepidus “warm;” PIE base *tep- “to be warm.”