thunderbolt

What it means

1. A flash of lightning accompanied by a crash of thunder.

   Our quiuering Lances ſhaking in the aire, / And bullets like Ioues dreadfull Thunderbolts, / Enrolde in flames and fiery ſmoldering miſtes, / Shall threat the Gods more than Cyclopian warres, […]

   c. 1587–1588 (date written), [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592, →OCLC; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire; London: Scolar Press, 1973, →ISBN, Act II, scene iii

   2 more examples

   And the sword that had visited Earth from so far away smote like the falling of thunderbolts [...] and the runes in Alveric’s far-travelled sword exulted, and roared at the elf-knight; until in the dark of the wood, amongst branches severed from disenchanted trees, with a blow like that of a thunderbolt riving an oak-tree, Alveric slew him.

   1924, Lord Dunsany, chapter III, in The King of Elfland's Daughter, New York: G.P. Puttnam's Sons, page 30

   He describes the operation thus: "The heavy ram employed to impart the finishing strokes, hoisted up with double purchase and snail's pace to the summit of the Piling Engine, and then falling down like a thunderbolt on the head of the devoted timber, driving it perhaps a single half inch in to the stratum below, is well calculated to put to the test the virtue of patience, while it illustrates the old adage of—slow and sure."

   1952 July, W. R. Watson, “Sankey Viaduct and Embankment”, in Railway Magazine, page 487

2. figurativelyAn event that is terrible, horrific or unexpected.

   News of the actress’s death came as a thunderbolt to her fans.

   2 more examples

   the Scipios' worth, those thunderbolts of war

   1697, Virgil, “(please specify the book number)”, in John Dryden, transl., The Works of Virgil: Containing His Pastorals, Georgics, and Æneis. […], London: […] Jacob Tonson, […], →OCLC

   A greater wreck, a deeper fall, / A shock to one—a thunderbolt to all.

   1819, Lord Byron, Mazeppa, a Poem, London: John Murray, […], →OCLC, stanza I, page 5, lines 13–14

3. Vehement threatening or censure; especially, ecclesiastical denunciation; fulmination.

   a thunder-bolt of warre Striking all Nations

   1627, G[eorge] H[akewill], An Apologie of the Power and Prouidence of God in the Gouernment of the World. […], Oxford, Oxfordshire: […] Iohn Lichfield and William Turner, […], →OCLC

In a sentence

Our quiuering Lances ſhaking in the aire, / And bullets like Ioues dreadfull Thunderbolts, / Enrolde in flames and fiery ſmoldering miſtes, / Shall threat the Gods more than Cyclopian warres, […]

c. 1587–1588 (date written), [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592, →OCLC; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire; London: Scolar Press, 1973, →ISBN, Act II, scene iii

Where it comes from

From thunder + bolt.