The words bold, bowled sound the same but have different meanings and spellings. Why do bold, bowled sound the same even though they are completely different words?
The answer is simple: bold, bowled are homophones of the English language.
Fearless and daring; courageous.
Requiring or exhibiting courage and bravery. See Synonyms at brave.
Unduly forward and brazen; impudent: a bold, sassy child.
Clear and distinct to the eye; conspicuous: a bold handwriting.
Describing the method of being dismissed in which the ball is bowled, and it hits and breaks the batsman's wicket.
Simple past tense and past participle of bowl.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition, from Wiktionary, Creative Commons Attribution/Share-Alike License 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").