- cruelty, mercilessness, pitilessness, ruthlessness - feelings of extreme heartlessness
--1 is a kind of heartlessness, coldheartedness, hardheartedness
- mercilessness, unmercifulness - inhumaneness evidenced by an unwillingness to be kind or forgiving
--2 is a kind of inhumaneness, inhumanity
Antonyms: mercifulness, mercy
--2 has particulars:pitilessness, ruthlessness; relentlessness, inexorability, inexorableness