The borrower grants the lender the mortgagee an interest in the property

"Elbar argued that, even if the bankruptcy court refused to modify the automatic stay to validate the Constable’s sale of the Debtor’s interest in the real property, the stay did not prevent Elbar from acquiring the
mortagee’s interest in the property. "
ftp://opinions.ca5.uscourts.gov/unpub/03/03-20347.0.wpd.pdf -

"While the promissory note may be your partner's sole responsibility, the mortagee's interest could be secured by the entire property. ..."
www.mbworld.org/.../158430-question-about-real-estate-laws-...

"First or Second Owner or their Mortgagee's interest in the Site as are disposed of (as the case may be) shall be released from the restrictions and ..."
planning.croydon.gov.uk/DocOnline/42610_2.pdf

"An asset that is used as a pledge to repay a loan. If you do not repay the loan according to the loan terms, the lender has the right to take the asset and sell it in order to cover the costs of your loan."

This notion is indeed closely linked to mortgage.

See _A treatise on the law of mortgages_, Volume 2
By Richard Holmes Coote, Sydney Edward Williams (1904)

HTH