Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
all-mains is an adjective meaning "used of a radio receiver that is adaptable to all voltages". It carries one recorded sense.
used of a radio receiver that is adaptable to all voltages
“an all-mains set”
United Kingdom
Definitions, synonyms and semantic relations for all-mains come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.