Answer:

dater

Answer	Crossword Clue
DATER	Rubber stamp, of sorts
DATER	One out with another
DATER	Mailroom gizmo

DATER	One who's taken out
DATER	Librarian's gadget
DATER	Office stamp
DATER	Receiving department gadget
DATER	Receiving desk gismo
DATER	Socially active sort
DATER	Carbon-14, maybe
DATER	Social activist?

DATER	Librarian's device
DATER	Post office device
DATER	Library stamp
DATER	Library device
DATER	Office machine
DATER	"Antiques Roadshow" expert
DATER	Stamp of a sort
DATER	Librarian's stamp

DATER	Mailroom stamp
DATER	Client of match.com
DATER	Postal stamp
DATER	Circulation desk gadget
DATER	Library implement
DATER	Postmaster's implement.
DATER	Post office stamp.
DATER	Postoffice stamp.

DATER	Instrument in post office.
DATER	Instrument used in postoffice.
DATER	Post office instrument.
DATER	Post office machine.
DATER	Useful rubber stamp.
DATER	Post office device.
DATER	Rubber stamp.
DATER	Time stamp.

DATER	Office instrument.
DATER	Office stampling apparatus.
DATER	Post Office device.
DATER	Office machine.
DATER	Office device.