not to give quarter
v. phr.
1. To be utterly unwilling to show mercy; not to allow a weaker or defeated party the chance to save themselves through escape.
The occupying foreign army gave no quarter
■ they took no prisoners, shot everyone, and made escape impossible.
2. To argue so forcefully during a negotiation or in a court of law as to make any counter-argument or counter-proposal impossible.
The District Attorney hammered away at the witnesses and gave no quarter to the attorney for the defense.

[TahlilGaran] English Idioms Dictionary ▲