Knock together Definition 1 of 2Pro Tip 1/3Speed Emphasized Use 'knock together' when something is made quickly, without much preparation or detail. She knocked together an outline for the essay in ten minutes. Pro Tip 2/3Informal Situations 'Knock together' is casual language, suitable for everyday conversation but not for formal writing. I'll knock together a playlist for the road trip. Pro Tip 3/3Temporary Fix Indicates a solution or creation may be makeshift or temporary, not permanent. He knocked together a shelter to stay dry during the rain.