Pitilessness and Unmercifulness

Pitilessness noun - Mercilessness characterized by a lack of pity.

Unmercifulness and pitilessness are semantically related. In some cases you can use "Unmercifulness" instead a noun "Pitilessness".

Unmercifulness noun - Inhumaneness evidenced by an unwillingness to be kind or forgiving.

Pitilessness and unmercifulness are semantically related. Sometimes you can replace term "Pitilessness" with "Unmercifulness", this nouns are similar.