say it: di-KOH-dur
decoder is a noun meaning "the kind of intellectual who converts messages from a code to plain text". It carries 2 recorded senses.
the kind of intellectual who converts messages from a code to plain text
a machine that converts a coded text into ordinary language
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 decoder 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.