dāruṇa : [adj.] severe; harsh; cruel.

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

Dāruṇa (adj.) [Ved. dāruṇa, to dāru ("strong as a tree"), cp. Gr. droo/n=i)sxuro/n Hesych; Lat. dūrus; Oir. dron (firm), Mir. dūr (hard) Ags. trum] strong, firm, severe; harsh, cruel, pitiless S i.101; ii.226; Sn 244; Dh 139; J iii.34; Pv iv.36 (=ghora PvA 251); Miln 117 (vāta); PvA 24, 52 (=ghora), 159 (sapatha a terrible oath= ghora), 181 (=kurūrin), 221 (˚kāraṇa); Sdhp 5, 78, 286.

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

dāruṇa: a. 強烈

巴漢辭典 編者：(斗六) 廖文燦

dāruṇá (cf. Uṇ. iii, 53)

dāruṇa

dā́ruṇa mf(ā, once ī)n. hard, harsh (opp. mṛdu) ŚBr. MBh. Suśr.

• rough, sharp, severe, cruel, pitiless

• dreadful, frightful

• intense, violent
Mn. MBh. R. Śak. Pañc. &c

• (in comp. or ○am before a vb. to express excellence or superiority, g. kāṣṭhâdi)

• m. Plumbago Zeylanica L.

• n. harshness, severity, horror MBh.

• ○ṇaka n. N. of a disease of the roots of the hair Suśr.

• ○ṇya n. harshness (of sound, TPrat. ii, 10)

Sanskrit-English Dictionary, by M. Monier William