The words adds, ads, adze sound the same but have different meanings and spellings. Why do adds, ads, adze sound the same even though they are completely different words?
The answer is simple: adds, ads, adze are homophones of the English language.
Plural form of add.
Third-person singular simple present indicative form of add.
Plural form of ad.
A cutting tool that has a curved blade set at a right angle to the handle and is used in shaping wood.
To shape a material using an adze.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.