Barrow: un túmulo, un montón de tierra sobre un cadáver, una tumba antigua. Wight: criatura, "pobre hombre". Stalker: acechador, perseguidor, alguien que espera sigiloso a alguien para cazarlo (Sorry, I love it speaking in Spanish xD)
Barrow: Mound of earth over a dead body, some kind of grave. Wight: A living creature, also used as a supernatural being, a Ghost or Witch. Stalker: Someone who prowls around,
sneaking to hunt someone or something.
Note: In Spanish, the word for Barrow-Wight is "Tumulario" which is one of my favourite LOTR translated words xD "Tumulario would mean something like "barrow-eer" as in "mountaneer".