unset [ -fmv ] name ...
       Each  named  parameter is unset.  Local  parameters
       even  if unset; they appear unset within scope, but
       value will still reappear when the scope ends.

       Individual elements of associative array parameters
       by  using  subscript  syntax on name, which  should
       the  entire command prefixed with noglob)  to  pro-
       script from filename generation.

       If  the -m flag is specified the arguments are tak-
       (should  be quoted) and all parameters with  match-
       unset.  Note that this cannot be used  when  unset-
       array elements, as the subscript will be treated as
       pattern.

       The  -v  flag  specifies that name refers to param-
       the default behaviour.

       unset -f is equivalent to unfunction.
