I. ˈthən-dər noun
Etymology: Middle English thoner, thunder, from Old English thunor; akin to Old High German thonar thunder, Latin tonare to thunder
Date: before 12th century
1. : the sound that follows a flash of lightning and is caused by sudden expansion of the air in the path of the electrical discharge
2. : a loud utterance or threat
3. : bang , rumble
the thunder of big guns
II. verb
( thun·dered ; thun·der·ing -d(ə-)riŋ)
Date: before 12th century
intransitive verb
1.
a. : to produce thunder — usually used impersonally
it thunder ed
b. : to give forth a sound that resembles thunder
horses thunder ed down the road
2. : roar , shout
transitive verb
1. : to utter loudly : roar
2. : to strike with a sound likened to thunder
• thun·der·er -dər-ər noun