Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
head-on is an adjective and adverb meaning "characterized by direct opposition". It carries 4 recorded senses.
in direct opposition; directly
“we must meet the problem head-on”
with the front foremost
“the cars collided head-on”
Definitions, synonyms and semantic relations for head-on come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.