The Collaborative International Dictionary of English v.0.48:

Happy \Hap"py\ (h[a^]p"p[y^]), a. [Compar. Happier
   (-p[i^]*[~e]r); superl. Happiest.] [From Hap chance.]
   1. Favored by hap, luck, or fortune; lucky; fortunate;
      successful; prosperous; satisfying desire; as, a happy
      expedient; a happy effort; a happy venture; a happy omen.
      [1913 Webster]

            Chymists have been more happy in finding experiments
            than the causes of them.              --Boyle.
      [1913 Webster]

   2. Experiencing the effect of favorable fortune; having the
      feeling arising from the consciousness of well-being or of
      enjoyment; enjoying good of any kind, as peace,
      tranquillity, comfort; contented; joyous; as, happy hours,
      happy thoughts.
      [1913 Webster]

            Happy is that people, whose God is the Lord. --Ps.
                                                  cxliv. 15.
      [1913 Webster]

            The learned is happy Nature to explore,
            The fool is happy that he knows no more. --Pope.
      [1913 Webster]

   3. Dexterous; ready; apt; felicitous.
      [1913 Webster]

            One gentleman is happy at a reply, another excels in
            a in a rejoinder.                     --Swift.
      [1913 Webster]

   Happy family, a collection of animals of different and
      hostile propensities living peaceably together in one
      cage. Used ironically of conventional alliances of persons
      who are in fact mutually repugnant.

   Happy-go-lucky, trusting to hap or luck; improvident;
      easy-going. "Happy-go-lucky carelessness." --W. Black.
      [1913 Webster]

WordNet (r) 3.0 (2006):

happy
    adj 1: enjoying or showing or marked by joy or pleasure; "a
           happy smile"; "spent many happy days on the beach"; "a
           happy marriage" [ant: unhappy]
    2: marked by good fortune; "a felicitous life"; "a happy
       outcome" [syn: felicitous, happy]
    3: eagerly disposed to act or to be of service; "glad to help"
       [syn: glad, happy]
    4: well expressed and to the point; "a happy turn of phrase"; "a
       few well-chosen words" [syn: happy, well-chosen]

Moby Thesaurus II by Grady Ward, 1.0:

219 Moby Thesaurus words for "happy":
   a propos, accepting, accidental, ad rem, adapted, addled,
   advantageous, advisable, applicable, apposite, appropriate,
   apropos, apt, at ease, auspicious, beaming, beatific, beatified,
   becoming, beery, befitting, bemused, beneficial, benign, benignant,
   besotted, blessed, blind drunk, blissful, blithe, blithesome,
   bright, bright and sunny, capering, casual, cheerful, cheery,
   chirping, civil, cock-a-hoop, cogent, comely, comfortable,
   composed, congruous, content, contented, convenient, convincing,
   correct, crapulent, crapulous, dancing, decent, decorous,
   delighted, desirable, dizzy, dovetailing, drenched, drunk, drunken,
   easy, easygoing, ecstatic, effective, effectual, efficacious,
   efficient, elated, eupeptic, euphoric, exalted, exhilarated,
   expedient, exuberant, exultant, fair, far-gone, favorable,
   favoring, feasible, felicitous, fit, fitted, fitten, fitting,
   flushed, flushed with joy, flustered, fortuitous, fortunate, fou,
   fructuous, full, full of promise, gay, geared, genial, genteel,
   giddy, glad, gladsome, gleeful, glorious, glowing, golden, good,
   gratified, high, hopeful, in good spirits, in high spirits,
   in liquor, in seventh heaven, incidental, inebriate, inebriated,
   inebrious, inspired, intoxicated, irrepressible, jolly, joyful,
   joyous, jubilant, just, just right, laughing, leaping,
   light-hearted, lighthearted, likely, lucky, maudlin, meet, mellow,
   merry, meshing, muddled, nappy, nice, of good cheer,
   of good comfort, of good omen, of happy portent, of promise,
   on cloud nine, on the button, opportune, optimistic, overjoyed,
   pat, pleasant, pleased, pleased as Punch, politic, profitable,
   promising, proper, propitious, prosperous, providential, purring,
   qualified, radiant, recommendable, reconciled, reeling, relevant,
   resigned, riant, right, ripe, rosy, sanguine, sanguineous,
   sans souci, satisfied, seasonable, seemly, shikker, singing,
   smiling, smirking, sodden, sortable, sotted, sparkling,
   starry-eyed, suitable, suited, suiting, sunny, tailored, telling,
   thrice happy, thrilled, tickled pink, tiddly, timely, tipsy,
   to be desired, to the point, to the purpose, uncomplaining,
   under the influence, unrepining, urbane, useful, well, well-chosen,
   well-expressed, well-put, well-timed, winsome, wise, without care,
   worthwhile



The Free On-line Dictionary of Computing (30 December 2018):

Happy

    A dyslexic acronym for "A Yacc-like Haskell Parser
   generator".

   An LALR1 grammar parser generator for Haskell.  Happy is
   written in Haskell, uses a parser generated by itself, and can
   be compiled using ghc, hbc or gofer.  Happy uses an
   implementation of monadic IO built on top of stream IO, but
   this should change when the Haskell 1.3 standard has been
   implemented.

   Version: 0.9 (1996-02-28).

   Happy is covered by the General Public License.

   (http://dcs.gla.ac.uk/fp/software/happy.html).

   (ftp://ftp.dcs.gla.ac.uk/pub/haskell/happy/).

   E-mail: , .

   (1996-03-21)


U.S. Gazetteer Places (2000):

Happy, TX -- U.S. town in Texas
   Population (2000):    647
   Housing Units (2000): 295
   Land area (2000):     1.065105 sq. miles (2.758608 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    1.065105 sq. miles (2.758608 sq. km)
   FIPS code:            32156
   Located within:       Texas (TX), FIPS 48
   Location:             34.743810 N, 101.857037 W
   ZIP Codes (1990):     79042
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Happy, TX
    Happy