Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
up-bow is a noun meaning "an upward stroke from the tip to the heel of the bow". It carries one recorded sense.
an upward stroke from the tip to the heel of the bow
Definitions, synonyms and semantic relations for up-bow come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.