Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
wattmeter is a noun meaning "an instrument for measuring in watts the flow of power in an electrical circuit". It carries one recorded sense.
an instrument for measuring in watts the flow of power in an electrical circuit
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 wattmeter come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.