Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
actinometrical is an adjective meaning "of or related to actinometry". It carries one recorded sense.
of or related to actinometry
Definitions, synonyms and semantic relations for actinometrical come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.