Definition of unpitiful in English:
unpitiful
adjective (ˌ)ʌnˈpɪtɪf(ʊ)l
Pitiless, unmerciful; harsh.
Origin
Late Middle English; earliest use found in Reginald Pecock (c1392–?1459), bishop of Chichester and religious author. Partly from unpity + -ful.