inextensible

Since the walls of the cell are inextensible, the quantity of water in the cell cannot increase.

While ligaments are pliable and flexible, permitting free movement, they are also wonderfully strong and inextensible.

The case of inextensible strings or chains is, however, so simple that it is generally included in expositions of pure statics.

A physical line is flexible and inextensible, and cannot be cut—so that no lap of it can be drawn through another.