海かい曹そうかいそうMeanings1nounpetty officer (navy)A non-commissioned officer rank in the Japan Maritime Self-Defense Force, equivalent to a petty officer in English-speaking navies.彼かれは海かい曹そうとして護ご衛えい艦かんに乗のり組くんでいる。He serves aboard a destroyer as a petty officer.