the GNU version of the Collaborative International Dictionary of English
adj. Not sparing; not parsimonious; liberal; profuse.
adj. Not merciful or forgiving.
The Century Dictionary and Cyclopedia
Not sparing; liberal; profuse; abundant: as, the unsparing use of money.
Not merciful; unmerciful: as, unsparing publicity.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. not forbearing; ruthless
adj. very generous
Word Usage
"The South's President Lee Myung-bak, during a visit to front-line troops Thursday, said that South Korea must make "unsparing" retaliation if it suffers another surprise attack."