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cavity; hollow; void
hollow (voice, smile, etc.); blank (eyes, look, etc.); vacant (expression, stare, etc.); empty (words, heart, etc.)
虚ろな目で宙を見た。
She stared blankly into space.
彼は虚ろな目で窓の外をじっと見つめていた。
He stared out the window with vacant eyes.
悲しみで心が虚ろになった。
His heart felt hollow from grief.