The words brassy, brassie sound the same but have different meanings and spellings. Why do brassy, brassie sound the same even though they are completely different words?
The answer is simple: brassy, brassie are homophones of the English language.
A golf club with a brass-plated sole and a wooden head, used for long low shots; a two wood.
Made of or decorated with brass.
Resembling brass, as in color.
Music Resembling or characterized by the sound of brass instruments: "The band was now playing some brassy march” ( Robert Penn Warren).
Cheap and showy; flashy.
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").