I didn’t know ruth was an actual word, always thought of ‘ruth’ as a name, like Ruth in the Bible. Apparently it is both now. This word actually originated from the same Ruth in the Bible!
ruth \ROOTH\ , noun;
1. Compassion or pity for another.
2. Sorrow or misery about one’s own misdeeds or flaws.
3. In the Bible, a Moabite woman who married Boaz and became an ancestor of David: the daughter-in-law of Naomi.
4. Book of the Bible bearing her name.
5. A female given name.
Even when she had been loudest in denouncing Ayala’s mutiny, her heart had melted in ruth because Ayala had been so unhappy.
— Anthony Trollope, Ayala’s Angel
Distinct from the Biblical figure, ruth is a descendent of the Middle English ruthe, from Old Norse hrygdh.