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!

Qenya 

ataltare

noun. collapse

A noun appearing as [ᴹQ.] ataltare “collapse” in the Quenya Verbal System (QVS) from 1948, a noun form of the verb atalta- (PE22/110). In Tolkien’s later writings, he used atalantë for “collapse” (MC/223).