say it: theh-RAWN
thereon is an adverb meaning "on that". It is pronounced /ðɛˈɹɔn/ — theh-RAWN. It carries one recorded sense.
Definitions, synonyms and semantic relations for thereon come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.