A modifier key whose main function is shifting between two or more functions of any of certain other keys (usually by pressing Shift and the other button simultaneously).
noun
A type of women's undergarment, a slip.
“Just last week she bought a new shift at the market.”
A change of workers, now specifically a set group of workers or period of working time.
“We'll work three shifts a day till the job's done.”
verb
(sometimes figurative) To move from one place to another; to redistribute.
“We'll have to shift these boxes to the downtown office.”