The Collaborative International Dictionary of English v.0.48:

Picnic \Pic"nic\, n. [Cf. F. piquenique. See Pick, v., and cf.
   Knickknack.]
   Formerly, an entertainment at which each person contributed
   some dish to a common table; now, an excursion or pleasure
   party in which the members partake of a collation or repast
   (usually in the open air, and from food carried by
   themselves).
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Picnic \Pic"nic\, v. i. [imp. & p. p. Picnicked; p. pr. & vb.
   n. Picnicking.]
   To go on a picnic, or pleasure excursion; to eat in public
   fashion.
   [1913 Webster]

WordNet (r) 3.0 (2006):

picnic
    n 1: a day devoted to an outdoor social gathering [syn: field
         day, outing, picnic]
    2: any undertaking that is easy to do; "marketing this product
       will be no picnic" [syn: cinch, breeze, picnic, snap,
       duck soup, child's play, pushover, walkover, piece
       of cake]
    3: any informal meal eaten outside or on an excursion
    v 1: eat alfresco, in the open air; "We picnicked near the lake
         on this gorgeous Sunday"

Moby Thesaurus II by Grady Ward, 1.0:

127 Moby Thesaurus words for "picnic":
   Cadmean victory, KO, Mardi Gras, Pyrrhic victory, Saturnalia,
   TV dinner, action, agonizing, agony, alfresco meal, arduous,
   ascendancy, ball, banquet, barbecue, big time, blowout, board,
   break bread with, breakfast, breeze, brunch, buffet supper,
   carnival, championship, cinch, clambake, coffee break, conquest,
   cook out, cookout, difficult, dine, dine out, diner, dinner,
   disagreeable, do, duck, easy target, easy thing, easy victory,
   eat out, elevenses, fair, feast, festival, festive occasion,
   festivity, fete, field day, fiesta, fish fry, fun, fun and games,
   funmaking, gala, gala affair, gala day, game, garden party,
   good time, grand slam, great doings, great fun, high jinks,
   high old time, high tea, high time, hot luncheon, jamboree, kermis,
   knockout, landslide, landslide victory, laughs, lead-pipe cinch,
   lovely time, lunch, luncheon, mash, mastery, meat breakfast,
   mess with, misfortune, moral victory, no picnic, painful, party,
   petit dejeuner, pie, piece of cake, play, pleasant time, pushover,
   rough, runaway victory, setup, sinecure, sitting duck, snap, sport,
   subdual, subduing, success, sup, supper, tea, tea break, teatime,
   tiffin, torture, torturous, total victory, tough, triumph, velvet,
   victory, walkaway, walkover, waygoose, wayzgoose, wiener roast,
   wienie roast, win, winning, winning streak



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

PEBCAK
PBCAK
PBKAC
PEBKAC
PICNIC

    (Or "PEBKAC", "PBCAK", "PBKAC") Tech support
   shorthand for "Problem (Exists) between Chair and Keyboard".

   An alternative is "PICNIC" - "Problem In Chair, Not In
   Computer".

   An acronym commonly used by helpdesk technicians to indicate
   that a problem is due to the user rather than the system.

   See also UBD.

   (2012-08-26)