In the recent past; only a short time ago.
On the day preceding today.
ETYM Old Eng. yisterdai, AS. geostran daeg, from geostran, geostra, giestran, gistran, gystran, yesterday (akin to Dutch gisteren, German gestern, Old High Germ. gestaron, Icel. gaer yesterday, to-morrow.
1. The day immediately before today.
2. The recent past.