A word in The Etymologies of the 1930s glossed “having trees, tree-grown”, a combination of ᴹQ. alda “tree” and the semi-suffix ᴹQ. -arwa “possessing, having”, serving as an example of that suffix’s use (Ety/ƷAR|GAR).
Quenya
aldarwa
having trees, tree-grown
aldarwa adj "having trees, tree-grown" (3AR). See -arwa.