non-commissioned officer
noun [ C ] uk/ˌnɒn.kə.mɪʃ.ənd ˈɒf.ɪ.sər/ us/ˌnɑːn.kə.mɪʃ.ənd ˈɑː.fɪ.sɚ/ (abbreviation NCO)
军士，士官
a member of the armed forces who has achieved the rank of officer by rising from the lower ranks rather than by receiving a commission
Compare: commissioned officer