Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
longwise is an adverb meaning "in the direction of the length". It carries one recorded sense.
in the direction of the length
“He cut the paper lengthwise”
Definitions, synonyms and semantic relations for longwise come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.