steal someone's thunder, to

Use or appropriate another's idea, especially to one's advantage, as in It was Harold's idea but they stole his thunder and turned it into a massive advertising campaign without giving him credit . This idiom comes from an actual incident in which playwright and critic John Dennis (1657-1734) devised a "thunder machine" (by rattling a sheet of tin backstage) for his play, Appius and Virginia (1709), and a few days later discovered the same device being used in a performance of Macbeth, whereupon he declared, "They steal my thunder."

If someone steals your thunder, they do something that stops you from getting attention or praise, often by doing something better or more exciting than you, or by doing what you had intended to do before you can do it. It's too late for rivals to take advantage. They couldn't steal our thunder. Note: You can also say that someone steals the thunder from you. I think O'Connor will steal some of the thunder from Read, as his book is out first. Note: This expression may come from an incident in the early 18th century. A British playwright, John Dennis, invented a new way of making the sound of thunder for his play `Appius and Virginia'. However, the play was unsuccessful and soon closed. Soon afterwards, Dennis went to see a production of `Macbeth' by another company and found that they had stolen his idea for making thunder sounds. He is said to have jumped up and accused them of stealing his thunder.

To ruin or detract from the effect of someone’s accomplishment by anticipating or copying it. This term originated in the early eighteenth-century theater, and the story behind it has been told by numerous writers. John Dennis (1657–1734), a critic and playwright, had devised a “thunder machine” for his play Appius and Virginia (1709); it consisted of rattling a sheet of tin backstage. The play failed, but a few nights later the same effect was used in a production of Macbeth, which Dennis attended and which prompted him to say, “They steal my thunder!” The term was subsequently used for similar situations and remained current long after its origin had been forgotten. Almost synonymous is the much newer to steal the show, meaning to outshine everyone else in a performance or at some event. It dates from the first half of the 1900s. The steal portion of this term implies that one is taking attention away from all the others.