נבב to make hollow, hollow out.
    — Qal occurs only in the pass. part. - נָבוּב (q.v.).
    — Pi. - נִבֵּב he made hollow, hollowed out.
    — Pu. - נֻבַּב was made hollow, was hollowed out. [Base of בִּיב (= pipe, gutter, sewer). Akka. ’imbūbu (= flute, pipe), whence Aram.-Syr. אַבּוּבָא (of s.m.), is of the same base. cp. also Akka. bābu (= door, gate) — whence Aram. בָּבָא (of s.m.) — which is shortened from nebābā (lit.: ‘hole, aperture’), from base נבב. cp. אַבּוּב, בָּבָא.]