--- In [log in to unmask], Elliott Lash <erelion12@Y...> wrote:

>You're right, while I dont know if the form *deru* is exactly
>correct...It's definitel more likely than deriving both "door" and
>Celtic words for "oak" from the same root.  (BTW, Irish for door is:
>dorus, probably from *dhwer*)


My only source of PIE roots is Pokorny's "Indogermanisches
Woerterbuch," admittedly a bit old (he didn't know about the
pharyngeals).  But I know of no other compendium.  I modify his roots
as I learn them here & there in journals.

"The American Heritage Dictionary" says the root means "hard, firm,
fast," resulting in words about wood & trees.

Pokorny gives the following variations of the PIE root for "tree":
deru, doru, dreu, dru, drou, drew@, druu, doru (drunos).  Some
interesting English derivations: tree, true, trust, tryst, trough,
tray, tar, endure, dryad, druid.

And he gives the following variations of the PIE root for "door,"
originally a plural word: dhwer, dhwor, dhur, dhwr.  Some interesting
English derivations: door, forest, foreclose, hors d'oeuvre, forum,