Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
uncompassionate is an adjective meaning "lacking compassion or feeling for others". It carries one recorded sense.
lacking compassion or feeling for others
“nor silver-shedding tears could penetrate her uncompassionate sire”
Definitions, synonyms and semantic relations for uncompassionate come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.