protective covering

As soon as it cools, it will harden and thus form a protective covering for the jelly.

The winter, or resting, spores are produced in the tissue of fruit and leaves and with a thick protective covering.

The tablets are coated with a protective covering in order that they may act on the intestine only.

The protoplasm forms the living organism; the coat is a kind of protective covering or shell.

At the outside is the bark, which forms a protective covering over the entire woody system.