sterile
    /ˈsterəl/ /Brit ˈstɛˌrajəl/
    
 
    
    adjective
    
    [more ~; most ~]
    
    not able to produce crops or plants
    
    
    
    not able to produce children, young animals, etc.
    
    
    
    
    
    not able to grow or develop
    
    
    
    clean and free of bacteria and germs
    
    
    
    
    
    not producing or containing new ideas, useful results, etc.
    
    
    
    very plain and not interesting or attractive