later on is an adverb meaning "happening at a time subsequent to a reference time". It carries one recorded sense.
happening at a time subsequent to a reference time
“he apologized subsequently”
“he's going to the store but he'll be back here later”
“it didn't happen until afterward”
“two hours after that”
Definitions, synonyms and semantic relations for later on come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.