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Webster 1913 Edition

Noun.

A secretary who is subordinate to the chief secretary; an assistant secretary;

as, an

undersecretary

of the Treasury

Noun.

A secretary subordinate to the principal secretary.

See also: Under Secretary

undersecretary ‎(plural undersecretaries)

An administrator immediately subordinate to a head of a government department or to a member of a cabinet

an administrator immediately subordinate to a head of a government department or to a member of a cabinet