The words whin, win, wynn sound the same but have different meanings and spellings. Why do whin, win, wynn sound the same even though they are completely different words?
The answer is simple: whin, win, wynn are homophones of the English language.
See gorse.
A whinstone.
To achieve victory or finish first in a competition.
To achieve success in an effort or venture: struggled to overcome the handicap and finally won.
To achieve victory or finish first in.
To receive as a prize or reward for performance.
An Old English rune having the sound (w) and used in Old English and early Middle English writing.
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.
If they are spelled the same then they are also homographs (and homonyms); if they are spelled differently then they are also heterographs (literally "different writing").