english
1
general::
Phrase(s): *behind bars in jail. (*Typically: be ~; put someone ~.) • Very soon, you will be behind bars for your crimes. • Max should be behind bars soon for his conviction on burglary charges.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
In prison, as in All murderers should be put behind bars for life. The bars here refer to the iron rods used to confine prisoners. [c. 1900]
American Heritage Idioms