mercy (N.)
                     //
               1
                     If you show mercy to someone, you do not punish them or treat them as severely as you
                     could.
                     He pleaded for mercy.
                                                                                                                                                                                                                                     UNCOUNT N
               2
                     If you are at the mercy of someone or something, they have complete power over
                     you.
                     This action would leave them at the mercy of industrialised countries.
                                                                                                                                                                                                 merciful  (adj.)