noun
1. : a shrub ( Viburnum prunifolium ) bearing cymes of white flowers and bluish black drupes
2.
a. : southern buckthorn
b. : false buckthorn
3. : either of two trees ( Bumelia tenax and B. lanuginosa ) of the southern United States
4. also black hawthorn : a hawthorn ( Crataegus douglasii ) of the western United States