the.com/petty officer

means A non-commissioned naval rank, roughly the Navy's equivalent of an Army sergeant, given authority over a specific trade or group of sailors.

from From French 'petit' (small), borrowed into English as 'petty' meaning minor or lesser. A petty officer was literally a 'lesser' officer — not a commissioned gentleman of the quarterdeck, but a seaman trusted with specialist duties like gunnery, navigation, or carpentry, and given authority to match. The rank name kept its diminutive root even as the job became anything but minor.