It means you used a constant where it's not being accessed. Specifically, you just did one of these:

$a{$b} = (3, 5, 7, 9, $c);
[download]

Which sets $a{$b} to $c, and ignores the 3, 5, 7, and 9.

Why you would do that, I'm not sure, but you just did. Maybe you meant to use curlies instead of parens around that list to make it into an anon hashref. Perhaps?

-- Randal L. Schwartz, Perl hacker