Middle Primitive Elvish
krumbā
adjective. *left
kurum
root. *left
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A (Noldorin-only?) root in The Etymologies of the 1930s whose derivatives have to do with “left” such as N. crom “left” and N. crumui “left-handed” (Ety/KURÚM). It seems this root had some “sinister” connotations, much like English/Latin uses of left, such as N. crumguru “wiley, sinister, guilty” (EtyAC/KUR). Left also had negative connotations in Tolkien’s earlier writings, such as G. gôg “clumsy; left (hand)” (GL/40). However, in the Ambidexters Sentence from 1969, Tolkien declared that Elves were ambidextrous and had no negative associations with “leftness”. I would recommend against using the root ᴹ√KURUM for the purposes of Neo-Eldarin, sticking to more neutral ᴹ√KHYAR instead.