Dictionary Definition:
Muddā (f.) [cp. (late?) Sk. mudrā] 1. a seal, stamp, impression; -- rāja˚ the royal seal DhA i.21. Also with ref. to the State Seal at Miln 280, 281 in cpds. muddakāma (amacca) & mudda -- paṭilābha. -- 2. the art of calculation mentioned as a noble craft (ukkaṭṭhaŋ sippaŋ) at Vin iv.7 (with gaṇanā & lekhā), as the first of the sippāni (with gaṇanā) at M i.85=Nd2 199. Further at Miln 3, 59, 78 sq., 178. Cp. BSk. mudrā in same sense (e. g. at Divy 3, 26, 58 in set lipyā, sankhyā, gaṇanā, m.). Bdhgh's expln of muddā D i.11 m.+gaṇanā (see DA i.95) as "hattha -- muddā -- gaṇanā" is doubtful; since at Miln 78 sq. muddā & gaṇanā are two quite diff. things. See also Franke, Dīgha trsl. p. 18, with note (he marks muddā "Finger -- Rechnen" with?); and cp. Kern, Toev. i.166 s. v. muddā. The Dial. i.21 trsl. "counting on the fingers" (see Dial. i.21, 22 with literature & more refs.). -- hattha˚ is signlanguage, gesture (lit. hand -- arithmetic), a means of communicating (question & answer) by signs, as clearly evident fr. J vi.364 (hattha -- muddāya naŋ pucchissāmi . . . muṭṭhiŋ akāsi, sā "ayaŋ me . . . pucchati" ti ñatvā hatthaŋ vikāsesi, so ñatvā . . .; he then asks by word of mouth). -- hattha -- muddaŋ karoti to make a sign, to beckon Jiii.528; cp. Vin v.163: na hatthavikāro kātabbo, na hattha -- muddā dassetabbā.
-- âdhikaraṇa the office of the keeper of the Privy Seal, Chancellorship Miln 281.