The words laches, latches sound the same but have different meanings and spellings. Why do laches, latches sound the same even though they are completely different words?
The answer is simple: laches, latches are homophones of the English language.
Negligence or undue delay in asserting a legal right or privilege.
Plural form of latch.
Third-person singular simple present indicative form of latch.
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").