gaster-
combining form 
or gastero-
Etymology: New Latin, from Greek gastero- belly, from gaster-, gastēr 
1. : ventral area 
< Gasteropoda >
< gasterostome >
2. : stomach 
< gasteralgia >
< Gasterophilus >
or gastero-
1.
< Gasteropoda >
< gasterostome >
2.
< gasteralgia >
< Gasterophilus >