出典:Wiktionary
grinds
Referring to used coffee as “coffee grinds” is proscribed, as a corruption of “coffee grounds”.[1] The degree of fineness of grinding is referred to as the grind, but ground coffee itself is prescribed to be referred to as grounds, generally either “fresh grounds” if unused, or “spent grounds” if used. The use of grounds to refer to dregs in a liquid dates to the 1300s.[2]