Definition of "on loan"

An ex-L.S.W.R. 0-6-0 goods engine, No. 0395, and a "Terrier" tank-engine, No. 2678, are now on loan.

1947 May and June, “Notes and News: The Kent & East Sussex Railway Today”, in Railway Magazine, page 182

Shortly thereafter Sugarman learned that the technology behind the pricey sunglasses wasn't on loan from NASA.

2002, Lou Harry, Sam Stall, As Seen on TV

As you generate your list of references check whether your library holds the books, and if so whether they are on loan.

2003, Nicholas Clifford, Gill Valentine, Key Methods in Geography, page 27

Bowman only hinted it was “on loan” from the Chatham Dockyard, so I didn't ask more.

2014, N. Jay Young, A Ship's Tale