from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
FUNCTUS OFFICIO. This term is applied to something which once had life and
power, but which now has no virtue whatsoever; as, for example, a warrant of
attorney on which a judgment has been entered, is, functus officio, and a
second judgment, cannot be entered by virtue of its authority. When
arbitrators cannot agree and choose an umpire, they are said to be functi
officio. Watts. on Arb. 94. If a bill of exchange be sent to the drawee, and
he passes it to the credit of the holder, it is functus officio, and cannot
be further negotiated. 5 Pick., 85. When an agent has completed the business
with which he was entrusted,.his agency is functus officio. 2 Bouv. Inst. n.
1382.