Typical People cover subject, informally

CELEB

Think of a short, casual term for someone famous that starts with "C."

The clue plays on the phrase "Typical People," which is a song by the band Orange Juice, often abbreviated as "OJ." The word "cover" hints at taking the outer letters of "OJ" (O and J), and "subject" refers to the letter "I" (as in "I" being a subject pronoun). "Informally" suggests combining these letters to form "OJI," which sounds like "celeb" when pronounced quickly, a common shorthand for "celebrity." So, the answer is "CELEB."