Pith/pɪθ/ Definition 1 of 4Pro Tip 1/2Brief and Powerful When referring to the key message, 'pith' highlights its concise and impactful nature. Her speech's pith moved everyone to act. Pro Tip 2/2Argument Clarity 'Pith of the argument' is used to discuss the clear, central idea of one's position. The pith of his thesis was his novel approach.