Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
semiaquatic is an adjective meaning "having an aquatic early or larval form and a terrestrial adult form". It carries 2 recorded senses.
having an aquatic early or larval form and a terrestrial adult form
biology
partially aquatic; living or growing partly on land and partly in water
“a marginal subaquatic flora”
biology
Definitions, synonyms and semantic relations for semiaquatic come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.