Barad would appear to imply a 'great towering building (fort, city, castle) tower', and also according to Tolkien, the root seems to express great height combined with strength, size, majesty. One of the Quenya words given for comparison is
Tarminas. This is according to Tolkien's
Words, Phrases and Passages, entry
Elbereth.
However I couldn't find something post-Lord of the Rings for
minas in this source (I
thought there was something here!), so going back in external time to
Etymologies (where we are dealing with N. meaning Noldorin not Sindarin, among other early differences)...
Quote:
|
MINI -- stand alone, (...) Q. mindo isolated tower N. min 'one, single, distinct unique' minnas 'tower'
|
Again I wish I could remember a later reference, but
with this (at least) I think we can see a semantic distinction.