ᴱ√LEHE³ root. “*smooth”
A root implied by entries the Gnomish Lexicon such as ᴱ✶leχa > G. lech/ᴱQ. lea “smooth, slippery”, ᴱ✶leχ-rā > G. lethrin “smooth, slippery, peril(o)us”, and ᴱ✶leχ-sa > G. lais “green sward, glade” (GL/53). There are no signs of this root in Tolkien’s later writing.
Reference ✧ GL/52 ✧ lech