'sharply-dropped' originates from the combination of 'sharp' and 'drop', where 'sharp' meant 'sudden or abrupt' and 'drop' meant 'to fall or descend'.

'sharp' and 'drop' were combined in modern English to describe a sudden decrease.

Initially, 'sharp' and 'drop' were used separately, but over time they evolved into a compound adjective to describe a sudden decrease.