Meanings
Based on a 1704 quote of John Dennis, a literary critic and minor playwright, who invented a novel method for creating a sound effect for thunder. The play in which he first introduced this method flopped, and the next play shown in the theatre was Macbeth. When the staging of Macbeth used his technique for simulating thunder, Dennis was reported in the press as jumping up and crying "How these rascals use me! They will not have my play, yet steal my thunder."
How to pronounce "steal someone's thunder":
AU
To appropriate someone's ideas or information, typically in order to look better at that person's expense.
To detract from someone's accomplishments or glory; to undermine.
