Overview
Adjutant is a military appointment given to an officer who assists the commanding officer with unit administration, mostly the management of human resources in an army unit. The term is used in French-speaking armed forces as a non-commissioned officer rank similar to a staff sergeant or warrant officer but is not equivalent to the role or appointment of an adjutant.
An adjutant general is commander of an army's administrative services.
Etymology
Adjutant comes from the Latin adiutāns, present participle of the verb adiūtāre, frequentative form of adiuvāre 'to help'; the Romans actually used adiūtor for the noun.
Military appointment
In various uniformed hierarchies, the term is used for number of functions, but generally as a principal aide to a commanding officer.
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