The term 'allow to use' can be broken down into three crossword solutions: LEND (4 letters), ADMIT (5 letters), and LET (3 letters). LEND means to give something temporarily, usually with the expectation that it will be returned. ADMIT means to accept or acknowledge something as true or valid. LET means to allow or permit something to happen. Together, these three words can be used to describe the action of allowing someone to use something.