taru-adjective, adverb taking the 'to' particle
billowing; rising in clouds
Literary or poetic word describing clouds, dust, or smoke rising thickly. Often used with と (べきべきと). Rare in everyday speech.
砂塵がべきべきと舞い上がる。
Dust billows up thickly.
山の向こうに雲がべきべきと湧き起こる。
Clouds billow up beyond the mountains.