There's a pretty famous story about Daniel Patrick Moynihan, which George F. Will relates in some detail:
[I]n 1976 was when Pat Moynihan, late of the Harvard faculty, won the Democratic nomination to run against the incumbent U.S. senator from New York, James Buckley. Over at Buckley headquarters Jim said he looked forward to running against Professor Moynihan, and he was sure Professor Moynihan would run the kind of high-level campaign one could expect from a Harvard professor. A few minutecs later, back at Moynihan headquarters Pat met the press. A reporter informed him that Jim Buckley was referring to him as "Professor Moynihan." Pat drew himself up to his full, considerable height and said with mock austerity, "Ah, the mudslinging has begun."
Well, I just came across a case that seriously considers the issue of whether (here, falsely) accusing someone of being an academic is defamatory. From Justice Christopher Barry-Smith in Tuvell v. Marshall (Mass. Super. Ct. 2017), a libel lawsuit that stemmed from a commenter banning controversy at the Ethics Alarms blog:
