Geology: A → sedimentary particle that is between 64 and 256 mm in size. Cobbles are larger than → pebbles but smaller than → boulders. Cobbles have typically been rounded by abrasion during sedimentary transport (geology.com/dictionary).
From M.E. cobill, kobill, probably a diminutive of M.E. *cob, *cobb, ultimately from Proto-Germanic *kubb- ("lump; round object") + -le.
Qolve, variant of gorde "kidney."