concertina movement

noun

1. a principle of table construction in which hinged sections of the frame, ordinarily folded inward out of sight, can be pulled into line with the parts of the frame ordinarily seen to permit the addition of leaves.

Example Sentences

Most methods of snake locomotion involve some pattern of curling up and straightening out again, such as concertina movement, scrunching their tails up toward their heads and pushing out headfirst, or lateral undulation, tensing and flexing alternating muscles in a sort of continuous wiggle.

From Slate