The words lose, loos sound the same but have different meanings and spellings. Why do lose, loos sound the same even though they are completely different words?
The answer is simple: lose, loos are homophones of the English language.
Praise, fame, reputation.
Plural form of loo.
To be unsuccessful in retaining possession of; mislay: He's always losing his car keys.
To be deprived of (something one has had): lost her art collection in the fire; lost her job.
To be left alone or desolate because of the death of: lost his wife.
To be unable to keep alive: a doctor who has lost very few patients.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, 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.