my @x = qw(a b c start end);
print "Values in my 'set':\n";
print "$_\n" for @x;

my $e = 'start';
@x = grep $e ne $_, @x;
print "\nValues after removing '$e':\n";
print "$_\n" for @x;

Values in my 'set':
a
b
c
start
end

Values after removing 'start':
a
b
c
end