Definition of ruthful in US English:

ruthful

adjective

archaic
  • 1Full of compassion or pity; compassionate; merciful. Also as noun (with the treated as plural): those people who are compassionate or merciful.

  • 2Of sounds, actions, a person's expression, etc.

Origin

Middle English; earliest use found in St. Margaret. From ruth + -ful.

Pronunciation

ruthful

/ˈruːθf(ʊ)l/