The words elicit, illicit sound the same but have different meanings and spellings. Why do elicit, illicit sound the same even though they are completely different words?
The answer is simple: elicit, illicit are homophones of the English language.
To bring or draw out (something latent); educe.
To arrive at (a truth, for example) by logic.
To call forth, draw out, or provoke (a reaction, for example). See Synonyms at evoke.
Not sanctioned by custom or law; unlawful.
Linguistics Improperly formed; ungrammatical.
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").