WordNet (r) 3.0 (2006):

coffee break
    n 1: a snack taken during a break in the work day; "a ten-minute
         coffee break"; "the British have tea breaks" [syn: coffee
         break, tea break]

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "coffee break":
   TV dinner, alfresco meal, barbecue, break, breakfast, breath,
   breather, breathing place, breathing space, breathing spell,
   breathing time, brunch, buffet supper, cigarette break, clambake,
   cocktail hour, cookout, diner, dinner, downtime, elevenses,
   enforced respite, fish fry, half time, half-time intermission,
   halt, happy hour, high tea, holiday, hot luncheon, interim,
   interlude, intermezzo, intermission, intermittence, interregnum,
   interruption, interval, letup, lull, lunch, luncheon, mash,
   meat breakfast, off-time, pause, petit dejeuner, picnic, plateau,
   point of repose, quiet spell, recess, relief, respite, rest,
   resting point, spell, stay, supper, surcease, suspension, tea,
   tea break, teatime, tiffin, time off, time out, vacation,
   wiener roast, wienie roast