Grounds
来自Big Physics
Old English grund, of Germanic origin; related to Dutch grond and German Grund .
wiktionary
grounds
From ground(“basis, surroundings”)
From ground, past participle of to grind
etymonline
grounds (n.)
"residue at the bottom of a liquid," mid-14c., perhaps from past tense of grind (v.). Other senses, such as "enclosed portion of land" (mid-15c.) are from ground (n.).
