Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
dead-on is an adjective meaning "accurate and to the point". It carries one recorded sense.
accurate and to the point
“a dead-on feel for characterization”
“She avoids big scenes...preferring to rely on small gestures and dead-on dialogue”
colloquialism
Definitions, synonyms and semantic relations for dead-on come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. .