An Etymological Dictionary of Astronomy and Astrophysics

To throw or bend back from a surface, specially light, sound, or heat.

Etymology (EN): M.E. reflecten, from L. reflectere “to bend back,” from → re- “back” + flectere “to bend.”

Etymology (PE): Bâztâbidan, from bâz-, → re- + tâbidan, variants tâftan “to shine,” tafsidan “to become hot;” 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.”