a.
1.
Liberal, profuse, lavish, bountiful, generous, ungrudging.
2.
Unmerciful, unforgiving, severe, harsh, rigorous, inexorable, relentless, ruthless, uncompromising.
UNSPARING
Meaning of UNSPARING in English
Soule. Dictionary of English synonyms. Словарь английских синонимов. 2012