Suffix[edit] -al. of or pertaining to; adjectival suffix appended to various words, often nouns, to make an adjective form. Often added to words of Latin origin, but used with other words also.
Remember: there is a difference between soil and dirt. Dirt is what you get on your clothes and hands while working in the soil. Soil is made up of elements that have been decomposing since the earth was created. Soil is composed of bedrock and mountain stones broken down over eons by wind and rain.
Definition of clay. 1  1a : an earthy material that is plastic when moist but hard when fired, that is composed mainly of fine particles of hydrous aluminum silicates and other minerals, and that is used for brick, tile, and pottery; specifically : soil composed chiefly of this material having particles less than a specified sizeb : earth, mud.