If something or someone lets water, air, or breath out, they allow it to flow out or escape. It lets sunlight in but doesn't let heat out Meer let out his breath in a long sigh
make known to the public information that was previously known only to a few people or that was meant to be kept a secret; "The auction house would not disclose the price at which the van Gogh had sold"; "The actress won't reveal how old she is"; "bring out the truth"; "he broke the news to her"
If you let out a particular sound, you make that sound. When she saw him, she let out a cry of horror. = give out see also let 14