Klein Dictionary, צלל ᴵ 1

צלל ᴵ to sink, plunge; to settle; to clear, clarify.
    — Qal - צָלַל he sank, plunged (a hapax legomenon in the Bible, occurring Ex. 15:10 in the form צָלֲלוּ).
    — Niph. - נִצְלַל settled, became clear.
    — Pi. - צִלֵּל he purified.
    — Pu. - צֻלַּל was purified.
    — Nith. - נִצְטַלֵּל PBH 1 he sank; MH 2 became clear.
    — Hiph. - הִצֽלִיל MH 1 he caused to sink; NH 2 he clarified, purified.
    — Hoph. - הֻצְלַל 1 was made to sink; 2 was clarified, was purified. [Aram. צְלַל, Syr. צַל (= clarified, filtered), Ethiop. ṣalalu (= swam, floated), Akka. ṣalālu (= settled, sank down), Amharic aṭlala (= he filtered). Prob. of imitative origin. cp. the related base צוּל.] Derivatives: צָלוּל ᴵ, צָלוּל ᴵᴵ, צִלּוּל ᴵ, צֽלִילָה, הַצֽלָלָה ᴵ, הִצְטַלְּלוּת, מִצְלוֹל ᴵ, צוֹלֵל ᴵ, צוֹלֶלֶת.