dhanu : [nt.] a bow.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Dhanu (nt.) [Sk. dhanus, to Ohg. tanna fir -- tree, also oak, orig tree in general, cp. dāru] a bow M i.429; J i.50, 150; ii.88; iv.327; PvA 285.
   -- kalāpa bow & quiver Vin ii.192; M i.86; ii.99; A iii.94; PvA 154; -- kāra a bow maker Miln 331; -- kārika N. of a tree J v.420; -- kārin=prec. J v.422 (=˚pāṭali); -- ggaha an archer D i.51; A ii.48; iv.107; J i.58, 356; ii.87, 88; iii.220 (dhanuggaha) J iii.322; v.129 (where 4 kinds are enumd); Vism 150 (in simile); DA i.156; -- takkāri (f.) a plant J vi.535; -- pāṭali N. of a tree J v.422; -- lakkhaṇa prophesying from marks on a bow D i.9.

Pali-English Dictionary, TW Rhys Davids, William Stede,

dhanu: n. 弓

巴漢辭典 編者：(斗六) 廖文燦

dhanu m. or (cf. Uṇ. i, 82) 2. dhanū f. (fr. √2. dhan?) a bow Hit. Śāntiś.
• a measure of 4 Hastas or cubits L. (cf. dhanv-antara below)
• the sign of the zodiac Sagittarius Priy. i, 5
• Buchanania Latifolia L.
• Semecarpus Anacardium L.
• (dhánu, or dhanū), f. a dry sandbank, a sandy shore [Eng. bight, Germ. Bucht] RV. AV. i, 17 (nom. ○nū́s)

Sanskrit-English Dictionary, by M. Monier William