let out (Noun) — A way out of an agreement or difficult situation. ex. "always write in a let-out clause"
let out (Verb) — Express audibly; make sounds (not necessarily words). ex. "She let out a big heavy sigh"
let out (Verb) — Make known to the public information that was previously known only to a few people or that was meant to be kept a secret. ex. "let out the evidence in the murder case"
let out (Verb) — Bring out of a specific state.
let out (Verb) — Make (clothes) larger. ex. "Let out that dress--I gained a lot of weight"