noun
1. : a small shrub to moderately large tree ( Laguncularia racemosa ) of the family Combretaceae that grows in brackish waters along the seacoasts of western Africa and tropical America, has flowers with fine small petals and a persistent top-shaped calyx, and is locally important as a source of tannins
2. : a small or medium-sized tree ( Avicennia officinalis ) growing in brackish water especially along the shores of the southwestern Pacific, having leaves white beneath, and yielding hard pale lumber and usable quantities of tannin ; broadly : any of several mangroves of the genus Avicennia