What is "retired flank"

Retired \Re*tired"\, a.

1. Private; secluded; quiet; as, a retired life; a person of retired habits.

   A retired part of the peninsula.
   --Hawthorne.

2. Withdrawn from active duty or business; as, a retired officer; a retired physician.

   Retired flank (Fort.), a flank bent inward toward the rear of the work.

   Retired list (Mil. & Naval), a list of officers, who, by reason of advanced age or other disability, are relieved from active service, but still receive a specified amount of pay from the government. [1913 Webster] -- Re*tired"ly, adv. -- Re*tired"ness, n.