The words holey, holy, wholly sound the same but have different meanings and spellings. Why do holey, holy, wholly sound the same even though they are completely different words?
The answer is simple: holey, holy, wholly are homophones of the English language.
Having holes or full of holes.
Belonging to, derived from, or associated with a divine power; sacred.
Regarded with or worthy of worship or veneration; revered: a holy book.
Living according to a strict or highly moral religious or spiritual system; saintly: a holy person.
Specified or set apart for a religious purpose: a holy place.
Completely; entirely: "The old American purposes are still wholly relevant” ( John F. Kennedy).
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.