Final answer:
In the story 'The Gift of the Magi,' 'pier-glass' refers to a mirror that was intended to hang on the wall. It is often used to describe a mirror set between two windows or architectural features.
Step-by-step explanation:
In the context of the story 'The Gift of the Magi,' the term 'pier-glass' refers to a mirror. It is used in paragraph 7 to describe a piece of furniture, specifically a full-length mirror that was intended to hang on the wall. The term 'pier-glass' is often used to refer to a mirror that is set in a frame and placed between two windows or other architectural features.