The officer who is in charge of the security and administration of a unit or establishment for a day at a time.
 Example sentencesExamples
-  Wieder, a German orderly officer in enemy intelligence recounts his disbelief of the sacrifices made.
 -  I cancelled plans to spend Christmas with my sister and her family and arranged that Smith should be orderly officer over Christmas.
 -  In the field sentries were traditionally visited by the orderly officer - ‘rounds’ - or by the field officer of the day - ‘grand rounds’ - to ensure that they were awake.
 -  I have been orderly officer this week, getting up at 6 30 every morning
 -  The colonel's orderly officer, Lieutenant Stranger, offers to buy it for his colonel.