thunderbolt. Classical ornament, an attribute of Jupiter, in the form of a spiral roll, pointed at both ends, often held in the talons of an eagle, or shown winged, with arrow-headed, forked, or zig-zag lightning-flashes. It occurs on the soffits of Classical cornices (e.g. Vignola's mutule Doric Order) and in Empire schemes of decoration.

thun·der·bolt / ˈ[unvoicedth]əndərˌbōlt/ • n. poetic/lit. a flash of lightning with a simultaneous crash of thunder. ∎  a supposed bolt or shaft believed to be the destructive agent in a lightning flash, esp. as an attribute of a god such as Jupiter or Thor. ∎  used in similes and comparisons to refer to a very sudden or unexpected event or item of news, esp. of an unpleasant nature: the full force of what she had been told hit her like a thunderbolt. ∎ inf. a very fast and powerful shot, throw, or stroke.

thunderbolt a supposed bolt or shaft believed to be the destructive agent in a lightning flash, especially as an attribute of a god such as Jupiter or Thor.