Deleted the specified variable from memory. Careful, there is no way to get it back after you do this. If classname is specified, only the variable within that class will be deleted. The variable name argument is expanded so you can remove a variable who's name is given by another variable. So normally you should not put the @ before the name of the variable you want to delete.
UNVAR example
#UNV tank removes the variable @tank
#VAR a 123
#VAR b a
#UNVAR @b removes the variable @a indirectly
#nnn