The words douse, dowse sound the same but have different meanings and spellings. Why do douse, dowse sound the same even though they are completely different words?
The answer is simple: douse, dowse are homophones of the English language.
To plunge into liquid; immerse. See Synonyms at dip.
To wet thoroughly; drench.
To put out (a light or fire); extinguish.
To become thoroughly wet.
To use a divining rod to search for underground water or minerals.
Variant of douse1.
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.