Lewis Short
(adjective) : illăcrĭmābĭlis (inl-), e, in-lacrimabilis.
* Unwept, unlamented, ἄκλαυστος: sed omnes illacrimabiles Urgentur ignotique longa Nocte,Hor. C. 4, 9, 26 (cf. indefletus, Ov. M. 7, 611).
* That is not or cannot be moved by tears, pitiless, inexorable: Pluto,Hor. C. 2, 14, 6: urna,Aus. Epit. 36, 3.
Charlton T. Lewis, Charles Short, A Latin Dictionary