The Collaborative International Dictionary of English v.0.48:

Glean \Glean\, v. t. [imp. & p. p. Gleaned; p. pr. & vb. n.
   Gleaning.] [OE. glenen, OF. glener, glaner, F. glaner, fr.
   LL. glenare; cf. W. glan clean, glanh?u to clean, purify, or
   AS. gelm, gilm, a hand?ul.]
   [1913 Webster]
   1. To gather after a reaper; to collect in scattered or
      fragmentary parcels, as the grain left by a reaper, or
      grapes left after the gathering.
      [1913 Webster]

            To glean the broken ears after the man
            That the main harvest reaps.          --Shak.
      [1913 Webster]

   2. To gather from (a field or vineyard) what is left.
      [1913 Webster]

   3. To collect with patient and minute labor; to pick out; to
      obtain.
      [1913 Webster]

            Content to glean what we can from . . . experiments.
                                                  --Locke.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Gleaning \Glean"ing\, n.
   The act of gathering after reapers; that which is collected
   by gleaning.
   [1913 Webster]

         Glenings of natural knowledge.           --Cook.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "gleaning":
   accumulation, amassment, ana, analects, anthology, assembling,
   bringing together, capital gains, cleanup, clear profit, clippings,
   collectanea, collection, crop, cumulation, cutting, cuttings,
   dividends, earnings, excerpta, excerpts, extracts, filthy lucre,
   florilegium, flowers, fragments, gain, gains, gathering, get,
   gettings, gleanings, gross, gross profit, harvest, harvesting,
   hoard, income, interest, killing, lucre, makings, miscellanea,
   miscellany, neat profit, net, net profit, nutting, paper profits,
   pelf, percentage, perk, perks, perquisite, pickings, proceeds,
   profit, profits, rake-off, reaping, receipts, return, returns,
   store, take, take-in, wealth, winnings



Bouvier's Law Dictionary, Revised 6th Ed (1856):

GLEANING. The act of gathering such grain in a field where it grew, as may,
have been left by the reapers after the sheaves were gathered.
     2. There is a custom in England, it is said, by which the poor are
allowed to enter and glean upon another's land after harvest without being
guilty of a trespass. 3 Bl. Com. 212 . But it has been decided that the
community are not entitled to claim this privilege as a right. 1 Hen. Bl.
51. In the United States, it is believed, no such right exists. This right
seems to have existed in some parts of France. Merl. Rep. mot Glanage. As to
whether gleaning would or would not amount to larceny, vide Woodf. Landl. &
Ten. 242; 2 Russ. on Cr. 99. The Jewish law may be found in the 19th chapter
of Leviticus, verses 9 and 10. See Ruth, ii. 2, 3; Isaiah, xvii. 6.