The words wax, whacks sound the same but have different meanings and spellings. Why do wax, whacks sound the same even though they are completely different words?
The answer is simple: wax, whacks are homophones of the English language.
Any of various natural, oily or greasy heat-sensitive substances, consisting of hydrocarbons or esters of fatty acids that are insoluble in water but soluble in nonpolar organic solvents.
A solid plastic or pliable liquid substance, such as ozocerite or paraffin, originating from petroleum and found in rock layers and used in paper coating, as insulation, in crayons, and often in medicinal preparations.
Plural form of whack.
Third-person singular simple present indicative form of whack.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition, 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.