There's a wider explanation on worden here, Leeneia, I was cutting too many corners for you - I read Mediaeval texts live, not through a grammar book. What's probably also missing (as ever in late mediaeval speech) is the verb "to be", omitted much like we use apostrophes.

Another way of deconstructing it is to knock the "n" off the end as it's almost certainly one of the German suffixes, "As Adam lay y-bounden", for instance. What you have left takes you to "wor" and thence to what I said.