David Astle is a full-time word nerd. Many will know him as the dictionary man on the TV show Letters and Numbers. Or maybe just DA, the devious crossword-setter in the Sydney Morning Herald and the Age. David also looks at language on ABC TV's News Breakfast, as well as devises a weekly 'Wordplay' newspaper column. Between puzzles, he's written half a dozen wordy-nerdy books for adults, including Riddledom, Cluetopia and Puzzled.