Meaning of “shift” - Learner’s Dictionary

shift

verb uk us /ʃɪft/
CHANGE [ I, T ]

to change something:

We are trying to shift the emphasis from curing illness to preventing it.
MOVE STH [ T ]

to move something to another place:

We need to shift all these boxes into the other room.
MOVE YOURSELF [ I, T ]

to move into a different position:

He shifted uncomfortably in his seat.
CHANGE SPEED [ T ] (also shift into) US

to change the position of the gears (= parts that control how fast the wheels turn) in a vehicle:

to shift gears
She shifted into neutral and turned off the engine.

(Definition of “shift verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)