吧嗒 (bā dā, despite the pinyin field showing only bā) is an onomatopoeia for short, crisp, repeating sounds like raindrops pattering, a light object clicking, or a quick smack of the lips. In sentences it often appears with 地 or 一声 to modify the verb: 雨吧嗒吧嗒地下 (rain patters down), 吧嗒一声锁上了 (clicked shut). It does not have a verb form in this entry; the related verb 'to pull on a pipe' belongs to a separate sense.