The words reave, reeve, rive sound the same but have different meanings and spellings. Why do reave, reeve, rive sound the same even though they are completely different words?
The answer is simple: reave, reeve, rive are homophones of the English language.
To seize and carry off forcibly.
To deprive (one) of something; bereave.
To rob, plunder, or pillage.
Archaic To break or tear apart.
The elected president of a town council in some parts of Canada.
Any of various minor officers of parishes or other local authorities.
A bailiff or steward of a manor in the later medieval period.
A high officer of local administration appointed by the Anglo-Saxon kings.
To rend or tear apart.
To break into pieces, as by a blow; cleave or split asunder.
To break or distress (the spirit, for example).
To be or become split.
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").