1. [n]  a deep prolonged loud noise
2. [n]  a booming or crashing noise caused by air expanding along the path of a bolt of lightning
3. [v]  utter words loudly and forcefully; "`Get out of here,' he roared."
4. [v]  to make or produce a loud noise; "The river thundered below"; "The engine roared as the driver pushed the car to full throttle."
5. [v]  move fast, noisily, and heavily; "The bus thundered down the road"
6. [v]  be the case that thunder is being heard; "Whenever it thunders, my dog crawls under the bed"

1. \Thun"der\, n. [OE. [thorn]under, [thorn]onder,
   [thorn]oner, AS. [thorn]unor; akin to [thorn]unian to
   stretch, to thunder, D. donder thunder, G. donner, OHG.
   donar, Icel. [thorn][=o]rr Thor, L. tonare to thunder,
   tonitrus thunder, Gr. to`nos a stretching, straining, Skr.
   tan to stretch. [root]52. See {Thin}, and cf. {Astonish},
   {Detonate}, {Intone}, {Thursday}, {Tone}.]
   1. The sound which follows a flash of lightning; the report
      of a discharge of atmospheric electricity.
   2. The discharge of electricity; a thunderbolt. [Obs.]
            The revenging gods 'Gainst parricides did all their
            thunders bend.                        --Shak.
   3. Any loud noise; as, the thunder of cannon.
   4. An alarming or statrling threat or denunciation.
            The thunders of the Vatican could no longer strike
            into the heart of princes.            --Prescott.
   {Thunder pumper}. (Zo["o]l.)
      (a) The croaker ({Haploidontus grunniens}).
      (b) The American bittern or stake-driver.
   {Thunder rod}, a lightning rod. [R.]
   {Thunder snake}. (Zo["o]l.)
      (a) The chicken, or milk, snake.
      (b) A small reddish ground snake ({Carphophis, or Celuta,
          am[oe]na}) native to the Eastern United States; --
          called also {worm snake}.
   {Thunder tube}, a fulgurite. See {Fulgurite}.
   

2. \Thun"der\, v. i. [imp. & p. p. {Thundered}; p. pr. &
   vb. n. {Thundering}.] [AS. [thorn]unrian. See {Thunder}, n.]
   1. To produce thunder; to sound, rattle, or roar, as a
      discharge of atmospheric electricity; -- often used
      impersonally; as, it thundered continuously.
            Canst thou thunder with a voice like him? --Job xl.
                                                  9.
   2. Fig.: To make a loud noise; esp. a heavy sound, of some
      continuance.
            His dreadful voice no more Would thunder in my ears.
                                                  --Milton.
   3. To utter violent denunciation.
   

3. \Thun"der\, v. t.
   To emit with noise and terror; to utter vehemently; to
   publish, as a threat or denunciation.
         Oracles severe Were daily thundered in our general's
         ear.                                     --Dryden.
         An archdeacon, as being a prelate, may thunder out an
         ecclesiastical censure.                  --Ayliffe.
   

often referred to in Scripture (Job 40:9; Ps. 77:18; 104:7). James and John were called by our Lord "sons of thunder" (Mark 3:17). In Job 39:19, instead of "thunder," as in the Authorized Version, the Revised Version translates (ra'amah) by "quivering main" (marg., "shaking"). Thunder accompanied the giving of the law at Sinai (Ex. 19:16). It was regarded as the voice of God (Job 37:2; Ps. 18:13; 81:7; comp. John 12:29). In answer to Samuel's prayer (1 Sam. 12:17, 18), God sent thunder, and "all the people greatly feared," for at such a season (the wheat-harvest) thunder and rain were almost unknown in Palestine.