The words gourd, gourde sound the same but have different meanings and spellings. Why do gourd, gourde sound the same even though they are completely different words?
The answer is simple: gourd, gourde are homophones of the English language.
Any of several trailing or climbing plants related to the pumpkin, squash, and cucumber and bearing fruits with a hard rind.
The fruit of such a plant, often of irregular and unusual shape.
The dried and hollowed-out shell of one of these fruits, often used as a drinking utensil.
off Slang Very foolish; crazy.
See Table at currency.
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").