Source : Free On-Line Dictionary of Computing

Hyperstrict
     
        A function which is hyperstrict in some argument will fully
        evaluate that argument.  To fully evaluate an object, evaluate
        it to WHNF and if it is a constructed data object (e.g. a list
        or tuple) then fully evaluate every component and so on
        recursively.  Thus a hyperstrict function will fail to
        terminate if its argument or any component or sub-component of
        its argument fails to terminate (i.e. if its argument is not
        "total").