Where does “planiloquus” come from?

planiloquus (Latin) comes from Latin plane, from Latin planus, from Proto-Italic plānos, from Proto-Indo-European pleh₂-no-s, from Proto-Indo-European pleh₂- — flat.

Ancestry of “planiloquus”, step by step

planiloquus traces back through two separate lines of ancestry.

via Latin plane

StepLanguageWordMeaning
1Latinplaneplainly to the senses or understanding, distinctly, intelligibly
2Latinplanuslevel, flat, even; intelligible, clear; a tramp,...
3Proto-Italicplānos
4Proto-Indo-Europeanpleh₂-no-sflattened
5Proto-Indo-Europeanpleh₂-flat

via Latin loquor

StepLanguageWordMeaning
1LatinloquorI say, speak, tell, talk; I declare, utter
2Proto-Italictlokʷōrto speak
3Proto-Indo-Europeantelkʷ-to talk
Every word from Proto-Indo-European pleh₂-Every word from Proto-Indo-European pleh₂-no-sEvery word from Proto-Italic plānos