1
general::
Phrase(s): *through the mill
Fig. badly treated; abused and exhausted. (Fig. on a grain mill. *Typically: be ~; go ~; put someone ~; send someone ~.) • This has been a rough day. I’ve really been through the mill. • This old car is banged up, and it hardly runs. We really put it through the mill.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Hardship or rough treatment, as in They put him through the mill, making him work at every one of the machines, or Fane was exhausted; she felt she'd been through the mill. This term alludes to being ground down like grain in a mill. [Late 1800s]
American Heritage Idioms