NOUN (2)

1. the day immediately before today;
- Example: "it was in yesterday's newspapers"

2. the recent past;
- Example: "yesterday's solutions are not good enough"
- Example: "we shared many yesterdays"


ADVERB (2)

1. on the day preceding today;
- Example: "yesterday the weather was beautiful"

2. in the recent past; only a short time ago;
- Example: "I was not born yesterday!"

The Collaborative International Dictionary of English v.0.48:

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]

The Collaborative International Dictionary of English v.0.48:

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

WordNet (r) 3.0 (2006):

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"

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "yesterday":
   aforetime, before, before now, beforetime, bygone days,
   bygone times, days gone by, dead past, earlier, erenow, erewhile,
   erst, foretime, former times, formerly, heretofore, historically,
   history, hitherto, in the past, in times past, lang syne,
   only yesterday, past, past history, past times, prehistorically,
   previously, priorly, recent past, recently, the irrevocable Past,
   the past, then, thou unrelenting past, times past, whilom,
   yesteryear, yore



The Devil's Dictionary (1881-1906):

YESTERDAY, n.  The infancy of youth, the youth of manhood, the entire
past of age.

    But yesterday I should have thought me blest
        To stand high-pinnacled upon the peak
        Of middle life and look adown the bleak
    And unfamiliar foreslope to the West,
    Where solemn shadows all the land invest
        And stilly voices, half-remembered, speak
        Unfinished prophecy, and witch-fires freak
    The haunted twilight of the Dark of Rest.
    Yea, yesterday my soul was all aflame
        To stay the shadow on the dial's face
    At manhood's noonmark!  Now, in God His name
        I chide aloud the little interspace
    Disparting me from Certitude, and fain
    Would know the dream and vision ne'er again.
                                                      Baruch Arnegriff

    It is said that in his last illness the poet Arnegriff was
attended at different times by seven doctors.