ALLUVIAL is a 8 letter word that starts with A.

1. \Al*lu"vi*al\, a. [Cf. F. alluvial. See {Alluvion}.]
   Pertaining to, contained in, or composed of, alluvium;
   relating to the deposits made by flowing water; washed away
   from one place and deposited in another; as, alluvial soil,
   mud, accumulations, deposits.
   
   

2. \Al*lu"vi*al\, n.
   Alluvial soil; specif., in Australia, gold-bearing alluvial
   soil.
   
   

1. Relating to something in streams and rivers or created/deposited by stream action.
2. Describes materials deposited by running water.