The words grip, grippe sound the same but have different meanings and spellings. Why do grip, grippe sound the same even though they are completely different words?
The answer is simple: grip, grippe are homophones of the English language.
A suitcase or valise.
A stagehand who helps in shifting scenery.
A tight hold; a firm grasp: a drowning swimmer now safely in the grip of a lifeguard.
The pressure or strength of such a grasp: a wrestler with an unmatched grip.
See influenza.
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").