sic / sick are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
sic: (verb) urge to attack someone. (adverb) intentionally so written (used after a printed word or phrase).
sick: (noun) people who are sick. (adjective) deeply affected by a strong feeling.
sic: s·IH·k
sick: s·IH·k
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)