The words hic, hick sound the same but have different meanings and spellings. Why do hic, hick sound the same even though they are completely different words?
The answer is simple: hic, hick are homophones of the English language.
An approximation to the sound of a hiccup, used e.g. to indicate drunkenness.
A person regarded as gullible or provincial: "New Yorkers had a horrid way of making people feel like hicks” ( Louis Auchincloss).
Provincial; unsophisticated: a hick town.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, 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").