find words not in an array

From: r (jk!ttop5_at_mnpX$.net)
Date: 03/28/05 

Date: Sun, 27 Mar 2005 22:09:51 -0600

if I have 2 arrays, @wordlist and @testlist, how can I create a third array
that contains the words from @testlist that are not common to @wordlist?

I thought I might use grep but can't figure it out.
Thanks,
r