Early Primitive Elvish
usu
root. get out, escape
ʒuðu Reconstructed
root. *burn
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!
The root ᴱ√USU⁽⁾ appeared in the Qenya Lexicon of the 1910s with the gloss “get out, escape” and derivatives like ᴱQ. usu- “he escapes” and ᴱQ. uswe “issue, outlet, escape” (QL/98). In the contemporaneous Gnomish Lexicon it had derivatives like G. us(ta)- “leave, depart” and G. uthwen “way out, exit; escape” (GL/75), the latter hinting that the root form may have been a blending with ✱ᴱ√UÞU. I think it is worth positing a Neo-Eldarin root ᴺ√UTH to salvage these early words for “escape”.