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!
Gnomish
thribin
adjective.lean
The Gnomish Lexicon of the 1910s had G. thribin “lean” (GL/73) likely based on the early root ᴱ√SIRIPI having to do with various stem/stalk words (QL/84).
Neo-Sindarin: I retain and adapt this early root as ᴺ√THIRIP “stalk”, so I would retain and adapt the Gnomish word as ᴺS. thriben “lean”, using -en as a more typical Sindarin adjective suffix.
The Gnomish Lexicon of the 1910s had G. thribin “lean” (GL/73) likely based on the early root ᴱ√SIRIPI having to do with various stem/stalk words (QL/84).
Neo-Sindarin: I retain and adapt this early root as ᴺ√THIRIP “stalk”, so I would retain and adapt the Gnomish word as ᴺS. thriben “lean”, using -en as a more typical Sindarin adjective suffix.