thunder

thunder sound produced along a path of a lightning flash, caused by the rapid heating and expansion of the adjacent air. Rolling thunder occurs either as a result of the time difference between sounds from the far and near end of a flash, or when mountains, layers of air, or other obstructions cause reverberations. Since sound travels about 1 mi in 5 sec, the distance between a lightning flash and an observer may be determined by counting the seconds between the flash and the thunder. Thunder as far distant as 10 to 15 mi (15 to 25 km) from an observer is usually not heard, even though lightning is often seen. See thunderstorm .

thunder traditionally regarded as the destructive agent producing the effects usually attributed to lightning. In biblical phrases, thunder denotes great force and energy, as in Job 39:19.
steal someone's thunder win praise for oneself by pre-empting someone else's attempt to impress. The phrase comes from an exclamation from the English dramatist John Dennis (1657–1734), on hearing his new thunder effects used at a performance of Macbeth, following the withdrawal of one of his own plays after only a short run.

See also blood-and-thunder, sons of thunder, the Thunderer, Thundering Legion.

thunder Used metaphorically for the voice of God (Job 37: 2, 5; Ps. 29: 3; John 12: 28–9) and the awesome holiness of God (Isa. 33: 3, REB).