shell-like

Shell-like describes something that resembles a shell in form, structure, or quality—typically suggesting a curved, hollow, or protective outer covering.

The term most often applies to shapes that echo the spiral or concave forms of seashells: shell-like ears, a shell-like enclosure.

It can also suggest fragility or thinness, as mollusk shells are both hard and delicate.

In British slang, a word in your shell-like means a private word in your ear.