What is the meaning of 直衣?

round-collared, skirted over-robe worn as daily wear by Japanese nobles from the Heian era. Unlike the 袍 (hō) the colour was not rank-prescribed. By custom white figured silk, lined with 二藍 (“overdye-purple”) in the winter, and overdye-purple silk-gauze in the summer. Worn with 指貫 (sashinuki) and 烏帽子 (eboshi).

Source: wiktionary.org