P.O.

Từ điển WordNet v3.1 - WordNet Dictionary

noun

a noncommissioned officer in the Navy or Coast Guard with a rank comparable to sergeant in the Army
• Syn:
petty officer, PO
• Hypernyms:
noncommissioned officer, noncom, enlisted officer
• Hyponyms:
master-at-arms, senior chief petty officer, SCPO