The words pomace, pumice sound the same but have different meanings and spellings. Why do pomace, pumice sound the same even though they are completely different words?
The answer is simple: pomace, pumice are homophones of the English language.
Pulpy material remaining after the extraction of oil from nuts, seeds, or fish.
The pulpy material remaining after the juice has been pressed from fruit, such as apples.
A light, porous, glassy lava, used in solid form as an abrasive and in powdered form as a polish and an abrasive.
To clean, polish, or smooth with pumice.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.