A noun for “homestead” in the Gnomish Lexicon of the 1910s, a combination of G. bar “home” with the noun suffix G. -wen (GL/21).
Gnomish
osta-
verb. to surround with walls, build up; to fortify, protect; to surround
barwen
noun. homestead
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A verb appearing as G. osta- “to surround with walls, build up; fortify, protect; surround” in the Gnomish Lexicon (GL/63), based on the early root ᴱ√OSO as suggested by Christopher Tolkien (LT2A/Belegost; QL/s71).
Neo-Sindarin: Since ᴹ√OS “round, about” appears in Tolkien’s later writings, I would retain ᴺS. osta- for purposes of Neo-Sindarin, originally with the sense “to surround”, later more specifically “surround with walls” and by extension “fortify, protect”, probably due to the influence ost “(fortified) town”.