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