Prickly ash (Zanthoxylum Americanum) and Poison ash (Rhus venenata) are shrubs of different families, somewhat resembling the true ashes in their foliage. -- Mountain ash. See Roman tree, and under Mountain.

Ash is used adjectively, or as the first part of a compound term] as, ash bud, ash wood, ash tree, etc.

* Ash is rarely used in the singular except in connection with chemical or geological products; as, soda ash, coal which yields a red ash, etc., or as a qualifying or combining word; as, ash bin, ash heap, ash hole, ash pan, ash pit, ash-grey, ash-colored, pearlash, potash.

Bone ash, burnt powered; bone earth. -- Volcanic ash. See under Ashes.