2 : a sudden sharp decrease in some quantity; "a drop of 57 points on the Dow Jones index"; "there was a drop in pressure in the pulmonary artery"; "a dip in prices"; "when that became known the price of their stock went into free fall"
3 : a sudden drop from an upright position
verbe
1 : move downward and lower, but not necessarily all the way
2 : move downward and lower, but not necessarily all the way
