The words friar, frier, fryer sound the same but have different meanings and spellings. Why do friar, frier, fryer sound the same even though they are completely different words?
The answer is simple: friar, frier, fryer are homophones of the English language.
A member of a usually mendicant Roman Catholic order.
Variant of fryer.
One that fries, as a deep utensil usually equipped with a basket and used for frying foods.
A small young chicken suitable for frying.
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.