The antonyms for the word "smooth down" are rough up, tousle, unkempt, rumple, and mess up. Rough up refers to making the surface of something uneven or bumpy. Tousle means to make something, especially hair, messy or disordered. Unkempt describes something that is messy, uncombed or untidy. Rumple means to wrinkle or crease something, while mess up refers to making something disorganized or untidy. These antonyms are useful when describing the opposite of smoothing something down, as they convey a sense of roughness or disorder.