say it: RAY-dee-oh
radio is a noun, verb and adjective meaning "medium for communication". It carries 5 recorded senses.
medium for communication
an electronic receiver that detects and demodulates and amplifies transmitted signals
a communication system based on broadcasting electromagnetic waves
indicating radiation or radioactivity
“radiochemistry”
combining form
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 radio 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.