grating the teeth, fretful
齷 centers on the physical act of grinding one's teeth, often from irritation or worry, giving rise to a fretful, agitated state.
齷 combines 齒 (teeth) with 屋, which likely contributes the sound アク. The character expresses the sound or action of grinding teeth.
The tooth radical 齒 on the left and 屋 (house) on the right suggest teeth grinding inside a house, perhaps from being cooped up and fretful.
For アク, imagine the sound of grinding teeth: 'ack!' like a sharp, fretful exclamation. Ack -> アク.
—
busily; sedulously; laboriously; feverishly; fussily; worrying (about little things)