verb

• (by extension) To lean, give way, or settle from a vertical position.
  "A building may sag one way or another."
• (figuratively) To lose firmness, elasticity, vigor, or a thriving state; to sink; to droop; to flag; to bend; to yield, as the mind or spirits, under the pressure of care, trouble, doubt, or the like; to be unsettled or unbalanced.
  "The mind I sway by, and the heart I bear, / Shall never sag with doubt nor shake with fear."
• (transitive) To cause to bend or give way; to load.
• (informal) To wear one's trousers so that their top is well below the waist.

phrase

• (on a letter) Initialism of Saint Anthony guide.

noun

• (LGBTQ) Initialism of straight-acting gay.

noun

• (astrology, informal) Clipping of Sagittarius.
  "For example, a Sag girl living on a farm could pick and chop cotton better than her brothers."