The words whoo, woo sound the same but have different meanings and spellings. Why do whoo, woo sound the same even though they are completely different words?
The answer is simple: whoo, woo are homophones of the English language.
An expression of delight.
The wailing cry of a ghost.
To seek the affection of with intent to romance.
To seek to achieve; try to gain.
To tempt or invite.
To entreat, solicit, or importune.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, 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.