Compound word. 
Don't mind the "x" and "z" if you look at the included image.
This might help. It is the image.
http://www.enchantedlearning.com/alphabet/wordforeachletter/compoundwords/answerstiny.GIF
        
             
        
        
        
To put abstract ideas into close-up words or a description that is more easily understood. Use D) concrete descriptions. Concrete descriptions seek to make a concept easily understood by the reader or listener.