1. not forbearing
ruthless

e.g. an unsparing critic

2. very generous

e.g. distributed gifts with a lavish hand
the critics were lavish in their praise
a munificent gift
his father gave him a half-dollar and his mother a quarter and he thought them munificent
prodigal praise
unsparing generosity
his unstinted devotion
called for unstinting aid to Britain

Synonym: lavishmunificentovergeneroustoo-generousunstintedunstinting