1. (geology) the matrix of fine-grained crystalline material in which larger crystals are embedded

Derived forms: groundmasses

Type of: igneous rock

Part of: porphyritic rock, porphyry

Encyclopedia: Groundmass

• feebleminded
• feeblemindedness
• feebleness
• feebly
• feed
• feed bunk
• feed grain
• feed in
• feed on
• feed upon
• feedback
• feedback circuit
• feedback loop
• feedbag
• feeder
• feeder line
• feeding
• feeding bottle
• feeding chair
• feeding frenzy
• feedlot
• feedstock
• feedstuff
• feel
• feel for