say it: KAHN-truh-ba-soon
contrabassoon is a noun meaning "the bassoon that is the largest instrument in the oboe family". It carries one recorded sense.
the bassoon that is the largest instrument in the oboe family
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 contrabassoon come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.