Traditionally, loan is the noun and lend is the verb. But while a minority of writers still observe this distinction, loan is increasingly used as a verb, and the trend is probably unstoppable. But if you wish to play it safe, it doesn’t hurt to abide by the traditional distinction, especially in formal writing.
Example
These publications don’t mind using loan as a verb:
Enter the premium finance companies that loan the money at bloated interest rates charged upfront and then collect their pound of flesh on a monthly basis. [Baltimore Sun]
The museum displayed it until 1950 and then loaned it to other museums until 1970, when it was returned. [Newsday]
In some publications, the verb loan is difficult to find, while the verb lend is common—for example:
The proposal was also intended to strengthen the rescue fund by allowing it to lend all its 440 billion euros, and perhaps use the money more flexibly. [Reuters]
Yunus created a bank that would lend small sums to such clients … [The Guardian]
Mortgage lenders are slashing the amount they lend to couples with children and older borrowers over the age of 55 are having trouble too. [Sydney Morning Herald]
