Qenya
onas(se)
adverb. the same place
on-
prefix. the same (oneness, uniqueness), identical
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 correlatives ᴹQ. onosse “the same place”, onas(se), or (archaic) †osse appeared in Demonstrative, Relative, and Correlative Stems (DRC) from 1948 (PE23/100, 111), a combination of ᴹQ. on- “same” and the locative suffix ᴹQ. -sse.
Neo-Quenya: For purposes of Neo-Quenya I would update this to ᴺQ. imassë “in the same place” using im- “same”.