Quenya
iquista
noun. request; if you please, please
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!
Early Quenya
iqista
noun. a request; if you please, please
A noun appearing as ᴱQ. iqista “a request” in the Qenya Lexicon of the 1910s under the early root ᴱ√IQI “request, ask for” (QL/43). Tolkien said that “by itself it = if you please, please”.
Neo-Quenya: I would retain ᴺQ. iquista “request” for purposes of Neo-Quenya along with related words, based on the Neo-Root ᴺ√IKWI(S). For “please” as marker of politeness, I would use the later formation mecin.