From WordNet (r) 3.0 (2006) [wn]:
yesterday
adv 1: on the day preceding today; "yesterday the weather was
beautiful"
2: in the recent past; only a short time ago; "I was not born
yesterday!"
n 1: the day immediately before today; "it was in yesterday's
newspapers"
2: the recent past; "yesterday's solutions are not good enough";
"we shared many yesterdays"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Yesterday \Yes"ter*day\, n. [OE. [yogh]isterdai, AS. geostran
d[ae]g, from geostran, geostra, giestran, gistran, gystran,
yesterday (akin to D. gisteren, G. gestern, OHG. gestaron,
Icel. g[ae]r yesterday, to-morrow, Goth. gistradagis
to-morrow, L. heri yesterday, Gr. ?, Skr. hyas) + d[ae]g day.
Cf. Hestern. ????.]
[1913 Webster]
1. The day last past; the day next before the present.
[1913 Webster]
All our yesterdays have lighted fools
The way to dusty death. --Shak.
[1913 Webster]
We are but of yesterday, and know nothing. --Job
viii. 9.
[1913 Webster]
2. Fig.: A recent time; time not long past.
[1913 Webster]
The proudest royal houses are but of yesterday, when
compared with the line of supreme pontiffs.
--Macaulay.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Yesterday \Yes"ter*day\, adv.
On the day last past; on the day preceding to-day; as, the
affair took place yesterday.
[1913 Webster] Yestereve