Clue: "Word that must be added to 1-, 8-, 65- and 66-Across for their clues to make sense [with a visual hint in the grid]"
"Word that must be added to 1-, 8-, 65- and 66-Across for their clues to make sense [with a visual hint in the grid]" is a New York Times crossword puzzle clue that we have seen 1 time.