Un-mildheort

According to the Old English Dictionary:

un-mildheort

adj. Hard-hearted, merciless, pitiless :-- Se déma betǽcþ ða unrihtwísan ðam unmildheortan wítnere, Homl. Ass. 8, 203. Ðe unmiltheortne welige inmisericordem divitem, Lk. Skt. p. 9, 2. Mé cóman tó Sílhearwan ... hí wǽron unmildheorta, and mé tugon tó ðære sweartan helle, Homl. Skt. i. 4, 289. un-mildheort