Klein Dictionary, רבב ᴵ 1

רבב ᴵ to be or become many or much, to be or become great.
    — Qal - רַב (formed from רבה) was much, was great.
    — Pi. - רִבֵּב he increased by ten thousand.
    — Pu. - רֻבַּב was increased by ten thousand (in the Bible occurring only Ps. 144:13 in the f. pl. part. מֽרֻבָּבוֹת).
    — Hiph. - הִרְבִּיב he increased by ten thousand. (The Pi., Pu. and Hiph. are denominated from רְבָבָה).
    — Shiph. (see . - שׁרבב ).
    — Pilp. (see . - רברב ). [Related to Aram. רְבַב, Syr. רַב (= was or became great), Arab. rabba (= he reared, increased; orig. ‘he made thick or dense’), Ethiop. rababa (= it expanded, spread). Related to base רבה ᴵ.] Derivatives: רַב ᴵ, רַב ᴵᴵ, רַב ᴵᴵᴵ, רֹב, רֽבָבָה, רִבּוֹ, רִבּוֹא, רִבּוֹן, רַבִּי, רַבָּן ᴵ, רַבָּן ᴵᴵ, מֵרַב, מְרֻבָּב. cp. רֽבִיבִים, רֵבָּא, אַדְרַבָּא. cp. also שׁרבב.