Real Dictionary

let out
phrasal verb: If something or someone lets water, air, or breath out, they allow it to flow out or escape.
phrasal verb: If you let out a particular sound, you make that sound.

let out in American English
to allow to flow, run, etc. away; release
to divulge; make known

let out in British English
to give vent to; emit
noun: a chance to escape

let-out in American English
adjective: processed by cutting parallel diagonal slashes into the pelt and sewing the slashed edges together to lengthen the pelt and to improve the appearance of the fur
noun: a means of escape; loophole

let-out in British English
noun: a chance to avoid having to do something that you do not wish to do