Definitions for "Handstamp"
1.) a hand-held device used by postal worker to cancel stamp or apply a postal marking 2.) the impression left by a handstamp on a cover.
Cancellation or overprint applied by hand to a cover or to a stamp.
Strictly speaking, the implement used to apply a postmark by hand, but often used loosely to signify the postmark itself. Historically, some overprints were applied by means of handstamps.