Meaning of lace-curtain

lace-cur•tain

Pronunciation: (lās'kûr"tn), [key]
— adj. Sometimes Offensive.
  1. characteristic of or aspiring to the standards and attributes of the middle class: Her latest novel traces the rise of a lace-curtain Irish family in Boston.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.