Christopher Culver has a post on a nice little linguistic find; he starts off with Eastern Mari omə̑ž ‘reed,’ a borrowing from Chuvash xămăš ‘bulrush,’ found in the Skvortsovs’ Chuvash-Russian dictionary, and continues:
But a few lines above it, one finds an entry for a remarkably similar word: xămăl ‘stubble (of cereals)’. Fedotov compares this to Tatar and Bashkir qamïl ‘bulrush’.
These must be the same words, both going back to Proto-Turkic *kamïš ‘grass stalk (or the like)’ and showing the ‑š ~ ‑l distinction that divides the family in two. Outside of Chuvash, the ‑l variant has no cognates outside of Volga Kipchak, and thus can be regarded as a Volga Bulgarian loan into Tatar and Bashkir. The ‑š variant, on the other hand, must be a loan from Volga Kipchak into Chuvash.
An amusing bit of trivia, two distantly related languages trading cognates with different meanings.
This is the kind of thing that makes me love historical linguistics.