Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
biodefence is a noun meaning "procedures involved in taking defensive measures against attacks using biological agents". It carries one recorded sense.
procedures involved in taking defensive measures against attacks using biological agents
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for biodefence come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.