Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
hard-hitting is an adjective meaning "characterized by or full of force and vigor". It carries 2 recorded senses.
aggressively and persistently persuasive
“a hard-hitting advertising campaign”
“a high-pressure salesman”
Definitions, synonyms and semantic relations for hard-hitting come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.