Real Dictionary

drift
verb: If someone or something drifts into a situation, they get into that situation in a way that is not planned or controlled.
verb: When something drifts somewhere, it is carried there by the movement of wind or water.

drift in American English
an act or instance of being driven or carried along, as by a current of air or water or by circumstances
to be carried along by or as by a current
intransitive verb: to be carried along by currents of water or air, or by the force of circumstances
noun: a driving movement or force; impulse; impetus; pressure
transitive verb: to carry along

drift in British English
to be carried along by or as if by currents of air or water or (of a current) to carry (a vessel, etc) along
noun: something piled up by the wind or current, such as a snowdrift

drift in the Oil and Gas Industry
noun: A drift is the degree to which a wellbore is not vertical.