merciless

The Inquiry was written at a time when its author had suffered from the tyranny and the mercilessness of booksellers.
Oliver Goldsmith|E. S. Lang Buckland
Every one there felt this, and knowing full well the mercilessness of the foe, all set to work in desperate earnest.
Stan Lynn|George Manville Fenn
The girl was appalled by the mercilessness of a destiny that had so outraged right.
Within the Law|Marvin Dana
I feel the mercilessness of the unknown powers weigh heavily upon me.
The Inferno|August Strindberg

It had come with a mercilessness which those who knew him regarded as only to be expected in a man of Pap Shaunbaum's record.
The Triumph of John Kars|Ridgwell Cullum

British Dictionary definitions for mercilessness

merciless

/ (ˈmɜːsɪlɪs) /

adjective

without mercy; pitiless, cruel, or heartless

Derived Formsmercilessly, adverbmercilessness, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for mercilessness

merciless

adj.

late 14c., see mercy + -less. Related: Mercilessly.