unhash [ -adfm ] name ...
       Remove the element named name from an internal hash table.   The
       default  is remove elements from the command hash table.  The -a
       option causes unhash to remove aliases.  The  -f  option  causes
       unhash  to remove shell functions.  The -d options causes unhash
       to remove named directories.  If the -m flag is given the  argu-
       ments  are taken as patterns (should be quoted) and all elements
       of the corresponding hash table  with  matching  names  will  be
       removed.

unalias
       Same as unhash -a.

unfunction
       Same as unhash -f.
