Leave, escape, as in With good conduct he'll get out of prison in a few months, or In case of a fire, we just want to get out alive. [c. 1300] This phrase is also used as an imperative, ordering someone to depart. For example, Get out! You've no business being in here. [c. 1700] Also see get out of, def. 1.
Become known, as in Somehow the secret got out. [Late 1800s] Also see out in the open.
get something out. Publish something, as in Once we get out the newsletter, we can concentrate on other projects. [Late 1700s]
Produce a sound, as in The singer had a sore throat and could hardly get out a note. [First half of 1800s] Also see the subsequent idioms beginning with get out.