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 

yuyallume

adverb. *both times

A correlative combination in Demonstrative, Relative, and Correlative Stems (DRC) from 1948 (PE23/110), a combination of ᴹQ. yúya “both” and ᴹQ. -llume “times”.

Neo-Quenya: For purposes of Neo-Quenya, I would distinguish it from [ᴱQ.] yullumë “twice” by assuming yuyallume means “✱both times”; compare ᴹQ. yuyan(an) “on both occasions”.