The words haik, hike sound the same but have different meanings and spellings. Why do haik, hike sound the same even though they are completely different words?
The answer is simple: haik, hike are homophones of the English language.
A large piece of cotton, silk, or wool cloth worn as an outer garment in Morocco.
To go on an extended walk for pleasure or exercise.
To rise, especially to rise upward out of place: My coat had hiked up in the back.
To increase or raise in amount, especially abruptly: shopkeepers who hiked their prices for the tourist trade.
To pull or raise with a sudden motion; hitch: hiked myself onto the stone wall; hiked up her knee socks.
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.