meerschaum n.

"pool, small lake, pond," from Old English mere "sea, ocean; lake, pool, pond, cistern," from Proto-Germanic *mari (source also of Old Norse marr, Old Saxon meri "sea," Middle Dutch maer, Dutch meer "lake, sea, pool," Old High German mari, German Meer "sea," Gothic marei "sea," mari-saiws "lake"), from PIE root *mori- "body of water." The larger sense of "sea, arm of the sea" has been obsolete since Middle English. Century Dictionary reports it "Not used in the U.S. except artificially in some local names, in imitation of British names."

early 15c. skimmen, "lift the scum from by a sliding motion, clear (a liquid) from matter floating on the surface" (the agent noun skimmer, for the utensil used, is attested from late 14c.), from Old French escumer "remove scum," from escume (Modern French écume) "scum," from a Germanic source (compare Old High German scum "scum," German Schaum; see scum).

The meaning "throw (a stone) so as to skip across the surface of (water)" is from 1610s. The meaning "move lightly and rapidly over the surface of" is from 1650s, from the motion involved in skimming liquid; that of "glance over carelessly, pass over lightly in perusal" (in reference to printed matter) is recorded by 1799. Related: Skimmed; skimming.