LET DOWN

{v. phr.} 1. To allow to descend; lower. * /Harry let the chain saw down on a rope and then climbed down himself./ 2. To relax; stop trying so hard; take it easy. * /The horse let down near the end of the race and lost./ * /The team let down in the fourth quarter because they were far ahead./ Compare: LET GO. 3. To fail to do as well as (someone) expected; disappoint. * /The team felt they had let the coach down./