Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
annihilative is an adjective meaning "wreaking or capable of wreaking complete destruction". It carries one recorded sense.
wreaking or capable of wreaking complete destruction
“possessing annihilative power”
“a devastating hurricane”
“the guns opened a withering fire”
Definitions, synonyms and semantic relations for annihilative come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.