1. A classification system for the antigens of human blood; used in blood transfusion therapy; four groups are A and B and AB and O
   - ABO blood group system, ABO system

Type of: classification system

• pucker
• puckerbush
• puckish
• puckishly
• puckishness
• pud
• pudden-head
• pudding
• pudding berry
• pudding head
• pudding pipe tree
• pudding stone
• pudding-face
• puddingheaded
• puddingwife
• puddle
• puddler
• pudency
• pudendal
• pudendal artery
• pudendal block
• pudendal cleavage
• pudendal cleft
• pudendal slit
• pudendal vein