Verbal equivalent of a thumbs-down

As a detective, the first step to solving the mystery of the crossword clue ‘Verbal equivalent of a thumbs-down’ is to gather all the available information and analyze it carefully. The phrase ‘thumbs-down’ immediately brings to mind the gesture used by ancient Romans to indicate disapproval. However, the clue specifically asks for a verbal equivalent of this gesture. In contemporary times, the most commonly used verbal expression of disapproval is ‘boo’. This insight, coupled with the understanding that the word ‘boo’ can be traced back to the 18th century, when it was used in the theatre to indicate disapproval, the solution to this crossword puzzle becomes clear. By piecing together the historical context associated with the word ‘boo’, coupled with the upbeat nature of the crossword, one can deduce that the answer is indeed ‘BOO’.