Definitions

1. noun

a deciduous tree of the birch family, particularly the black alder (Alnus glutinosa), having smooth, greyish-brown bark and catkin-like cones.

“The alder trees were abundant along the riverbank.”

2. noun

a reddish-brown dye obtained from the bark of the alder tree.

“The alder was used as a natural dye to colour the fabric.”

3. verb

to make something smooth and flat, typically by rubbing it with a tool.

“The craftsman aldered the wooden surface to give it a glossy finish.”