A challenge to a duel is an invitation to engage in a fight or competition. The term can be broken down into three parts: SLAP (4 letters), SLAPS (5 letters), and DRAW (4 letters). SLAP is an acronym for 'Strike Liberally And Provoke', which is a phrase used to describe the act of challenging someone to a duel. SLAPS stands for 'Strike Liberally And Provoke Someone', which is a more aggressive version of the same phrase. Finally, DRAW is an acronym for 'Duel Rules Are Written', which is a reminder that all duels must follow certain rules.