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1. Any of various common orange trees yielding sour or bitter fruit; used as grafting stock
   - sour orange, bitter orange, bitter orange tree, bigarade, marmalade orange, Citrus aurantium
    
2. Highly acidic orange used especially in marmalade
   - bitter orange, sour orange

Derived forms: Seville oranges

Type of: orange, orange tree

Part of: genus Citrus

Encyclopedia: Seville orange