The Collaborative International Dictionary of English v.0.48:

Postprandial \Post*pran"di*al\, a. [Pref. post- + prandial.]
   Happening, or done, after dinner; after-dinner; as,
   postprandial speeches.
   [1913 Webster]

WordNet (r) 3.0 (2006):

postprandial
    adj 1: following a meal (especially dinner); "his postprandial
           cigar"; "took a postprandial walk" [ant: preprandial]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "postprandial":
   after the Fall, after the flood, after the war, after-dinner,
   afterdeath, cannibal, cannibalistic, carnivorous, commensal,
   dietetic, dining, eating, feeding, flesh-eating, fruitarian,
   gastronomic, gluttonous, grain-eating, graminivorous, granivorous,
   grass-eating, herbivorous, insect-eating, insectivorous,
   lactovegetarian, man-eating, meat-eating, mensal, nourishing,
   nutritious, omnivorous, omophagous, pantophagous, phytivorous,
   phytophagous, plant-eating, postbellum, postcenal, postcibal,
   postdiluvial, postdiluvian, posthumous, postlapsarian, postwar,
   prandial, predacious, preprandial, vegetable-eating, vegetarian