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

• unmethodical
• unmilitary
• unmindful
• unmindfully
• unmindfulness
• unmined
• unmingled
• unmissable
• unmistakable
• unmistakably
• unmistakeable
• unmitigable
• unmitigated
• unmixable
• unmixed
• unmoderated
• unmodernised
• unmodernized
• unmodifiable
• unmodified
• unmodulated
• unmolested
• unmoor
• unmoral
• unmortgaged