Took a nosedive is an idiom that means to suddenly and drastically decrease in value, quality, or popularity. It can be used to describe a variety of situations, such as a stock market crash, a decline in a company's profits, or a celebrity's fall from grace. The two crossword solutions for this term are 'FELL' (4 letters) and 'plunged' (7 letters). Both words accurately describe the sudden and drastic decrease in value, quality, or popularity that is implied by the phrase 'took a nosedive'.