| 1. | a disease of peaches, apples, roses, grapes, etc., characterized by the formation of galls on the roots or stems usually at or below ground level, caused by a bacterium, Agrobacterium tumefaciens. |
| 2. | the gall itself. |
| crown gall n. A widespread disease of numerous plants caused by the bacterium Agrobacterium tumefaciens and characterized by formation of galls especially at the junction of root and stem. |