Part of a rifle, underneath the barrel, where it is supported by the hand.
from Wiktionary, Creative Commons Attribution/Share-Alike License
The one on the auction description but still smallish, the forend is sorta plain but the butt is wonderfully figured!
Whether I use bags or not, I still run my sling tight and have the forend resting on my palm under the sling.
I really like the spiral fluting. .make mine a stainless in 300 Wby, 24 inch barrel, a checkered nutmeg stock with blackened forend tip and a limbsaver or pachmyr pad ..
If you want to retain a wood stock with an increased length of pull, you may want to consider Boyd's buttstock for the Lee Enfield and stain it to match the existing forend.
I do agree that some semi autos are tough to open, too bad the manufacturers couldn't make the forend like the Benelli Tactical Shotgun the military uses.