outer end of the eyebrow; tail of the eyebrow
Refers specifically to the outer tip of the eyebrow, away from the nose. Often used in makeup or facial description contexts.
眉尻を少し下げると優しい印象になります。
Lowering the outer ends of your eyebrows a little gives a gentle impression.
彼女は眉尻
She draws in the tails of her eyebrows to give her face more definition.
Compound of 眉 (mayu, 'eyebrow') and 尻 (shiri, 'buttocks, end'), literally 'eyebrow end'.