tanu : [adj.] thin; slender.

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

Tanu [Vedic tanu, f. tanvī; also n. tanu & tanū (f.) body *ten (see tanoti)=Gr. tanu -- , Lat. tenuis, Ohg. dunni, E. thin] 1. (adj.) thin, tender, small, slender Vv 162 (vara˚ graceful=uttamarūpa -- dhara VvA 79; perhaps to 2); PvA 46 (of hair: fine+mudhu). -- 2. (n. nt.) body (orig. slender part of the body=waist) Vv 537 (kañcana˚); Pv i.121; Vism 79 (uju+). Cp. tanutara.
   -- karaṇa making thinner, reducing, diminishing Vin ii.316 (Bdhgh on CV. v.9, 2); -- bhāva decrease Pug 17; -- bhūta decreased, diminished Pug 17; esp. in phrase ˚soka with diminished grief, having one's grief allayed DhA iii.176; PvA 38.

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