WordNet sense 1 ((physics) the angle that a magnetic needle makes with the plane of the horizon):

inclination, angle of dip, magnetic dip, magnetic inclination

WordNet sense 2 (a thief who steals from the pockets or purses of others in public places):

pickpocket, cutpurse

WordNet sense 3 (a sudden sharp decrease in some quantity):

drop, fall, free fall

WordNet sense 4 (switch (a car's headlights) from a higher to a lower beam):

dim

WordNet sense 5 (appear to move downward):

sink

WordNet sense 6 (dip into a liquid):

douse, duck

WordNet sense 7 (immerse briefly into a liquid so as to wet, coat, or saturate):

dunk, plunge, souse