The earliest occurrence of the word "moat" that I could find online from Buffett is from 1986: https://www.berkshirehathaway.com/letters/1986.html https://www.b

The earliest occurrence of the word "moat" that I could find online from Buffett is from 1986: https://www.berkshirehathaway.com/letters/1986.html https://www.berkshirehathaway.com/letters/1986.html That shareholder letter is charmingly old-school. Unfortunately letters before 1977 weren't available online so I wasn't able to search. It also helps that I've been to several cities with an actual moat so this word is familiar to me.