What is the meaning of the word "half-length"?

Definitions:

  1. a portrait showing the body from only the waist up copy to clipboard noun
    • I purchased a halflength depicting the monarch. copy to clipboard
  2. abridged to half its original length copy to clipboard adjective
    • My copy of War and Peace was halflength. copy to clipboard
  3. representing only the upper half of the body copy to clipboard adjective
    • There was a beautiful halflength portrait in the museum. copy to clipboard