eryn ~ wood
glad ~ wood
taur ~ great wood, forest
tawar ~ great wood, forest (also pertains to the material)
Eryn Laer, Lothlórien: Laer meaning summer or song. Summer Wood or Wood of Song.
Taur Hith, Lothlórien: Hith meaning mist or fog. Forest of Mist.
Taur Ornolf, Trollshaws: Orn meaning large tree. I think olf is from golf meaning branch. Perhaps Forest of large branching trees.
Gladdalf, Trollshaws: Dalf meaning flat field or land (from talf). Wood on flat land (doesn’t sound very poetic so I suspect there is a better translation!)
(Translations are from the Appendix: Elements in Quenya and Sindarin, The Silmarillion, J.R. R. Tolkien or Hiswelókë’s Sindarin Dictionary. I am not an expert at all – if you see any mistakes please let me know!)