Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
by-catch is a noun meaning "unwanted marine creatures that are caught in the nets while fishing for another species". It carries one recorded sense.
unwanted marine creatures that are caught in the nets while fishing for another species
“thousands of dolphins and porpoises and whales are killed as part of the by-catch each year”
Definitions, synonyms and semantic relations for by-catch come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.