Mesogastric \Mes`o*gas"tric\, a. [Meso- + gastric.] 1. (Anat.) (a) Of or pertaining to the middle region of the abdomen, or of the stomach. (b) Of or pertaining to the mesogaster. 2. (Zo["o]l.) Of or pertaining to the middle gastric lobe of the carapace of a crab.