Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
turnbuckle is a noun meaning "an oblong metal coupling with a swivel at one end and an internal thread at the other into which a threaded rod can be screwed in order to form a unit that can be adjusted for length or tension". It carries one recorded sense.
an oblong metal coupling with a swivel at one end and an internal thread at the other into which a threaded rod can be screwed in order to form a unit that can be adjusted for length or tension
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 turnbuckle come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.