A loud rumbling sound emitted by rapidly expanding air along the path of the electrical discharge of lightning.
M.E. thonder, thunder, O.E. thunor, from P.Gmc. *thunraz (cf. O.Fris. thuner, M.Du. donre, Du. donder, O.H.G. donar, Ger. Donner "thunder"), cognate with Pers. tondar, as below.
Tondar; Mid.Pers. tndwr, Sogdian twntr; cf. Skt. stan- "to thunder, resound," tanyati "thunders, roars," tanyu- "thundering," stanatha- "thunder;" L. tonare "to thunder," tonitrus "thunder" (Fr. tonnerre); PIE base *(s)tene- "to resound, thunder."
tondar-tuf, tufân-e tondari
A → storm of → thunder and → lightning. Thunderstorms are associated with → convective clouds (Cumulonimbus) and are often accompanied by → precipitation. They are usually short-lived and hit on only a small area.
Tondar-tuf, tufân-e tondari, from tondar, → thunder + tuf stem of tufidan "to roar, to raise a tumult," tufân "storm, the roaring of the sea, the confused hum of men or animals." This Persian word may be related to Gk. typhon "whirlwind, mythical monster associated with tempests."