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