Maybe this is a dumb question, but:

I want to use some adhesive in certain parts of my staple down 3/8" engineered install (first/last rows where I can't staple and where I change tongue/groove directions).

I was using PL 400 (which I understand is a urethane adhesive), no problem, works well. However, I ran out and HD didn't have any more, so I got some "PL Polyurethane" adhesive. It says "100% polyurethane".

So my question is: is "urethane" and "polyurethane" the same thing? Can I safely use polyurethane on the engineered wood.

Thanks

Yes, it is actually a better product for what your trying to do.