Brawniness refers to physical strength or muscular power. In its opposite, weakness or fragility, one can find antonyms. Other antonyms for brawniness include delicacy, frailty, debility, and feebleness. These words describe the opposite of brawniness, implying that someone is not strong, physically fit, or muscular. Other antonyms that relate to brawniness can include terms like slenderness, skinniness, leanness, or delicate physique. Using these antonyms can help convey the opposite meaning of brawniness, giving readers a clearer picture of what you are trying to convey in your writing.