1
general::
Phrase(s): let it all hang out
Inf. to be yourself, assuming that you generally are not; to become totally relaxed and unpretentious. • Come on. Relax! Let it all hang out. • I tried to let it all hang out, but I still felt out of place.
McGrawhill's American Idioms And Phrasal Verbs
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general::
Be totally candid in expressing feelings and opinions; hold nothing back. For example, The psychiatrist urged him not to spare any details, to let it all hang out. [Slang; late 1960s]
American Heritage Idioms