thunder
n. uncountablen. the loud noise that you hear in the sky during a storm. It usually happens right after you see a flash of lightning.
n. the loud rumbling or crashing sound caused by the expansion of air that has been rapidly heated by lightning.
The loud thunder woke me up in the middle of the night.
We decided to stay inside because we could hear thunder rolling in the distance.
The sudden crack of thunder echoed through the valley, signaling the arrival of a storm that would last for several hours.
From Middle English thunder, thonder, thundre, thonre, thunnere, þunre, from Old English þunor (“thunder”), from Proto-West Germanic þunr, from Proto-Germanic þunraz, from Proto-Indo-European (s)ten-, (s)tenh₂- (“to thunder”). Compare astound, astonish, stun. Germanic cognates include West Frisian tonger, Dutch donder, German Donner, Old Norse Þórr (English Thor), Danish torden, Norwegian Nynorsk tore. Other cognates include Persian تندر (tondar), Latin tonō, detonō, Ancient Greek στένω (sténō), στενάζω (stenázō), στόνος (stónos), Στέντωρ (Sténtōr), Irish torann, Welsh taran, Gaulish Taranis. Doublet of donner, Thunor, and Thor.
From Middle English thundren, from Old English þunrian (“to thunder”), from Proto-West Germanic þunrōn, from Proto-Germanic þunrōną (“to thunder”).
Often used with the verb 'to roll' or 'to crash'; can be used as a countable noun when referring to a specific sound ('a clap of thunder').