Lewis Short
(adjective) : immĭsĕrĭcors (inm-), ordis, inmisericors
* Pitiless, merciless (very rare, but class.): ipsum immisericordem, superbum fuisse,Cic. Inv. 2, 36, 108: judex immisericors atque inexorabilis contra improbos,Gell. 14, 4, 3.—Of things: flucti (i. e. fluctus) inmisericordes jacere, Att. ap. Non. 488, 12 (Fragm. Trag. v. 33 Rib.); Vulg. Jer. 50, 42.—* Adv.: immĭsĕrĭcordĭter, unmercifully: factum a vobis duriter immisericorditerque,Ter. Ad. 4, 4, 28.
Charlton T. Lewis, Charles Short, A Latin Dictionary