To cover the back of; to load or burden.

To write upon the back or outside of a paper or letter,
as a direction, heading, memorandum, or address.

To write one’s name, alone or with other words, upon
the back of (a paper), for the purpose of transferring it, or to secure
the payment of a /ote, draft, or the like; to guarantee the payment,
fulfillment, performance, or validity of, or to certify something upon
the back of (a check, draft, writ, warrant of arrest, etc.).