Bilateral (adjective)

1. Involving two parties or sides.
2. Relating to or affecting both sides of a body or an organism.

Origin:

From the latin word "bis" meaning "two" and "latus" meaning "side".

Examples:

1. The treaty was signed in a bilateral ceremony.
2. The bilateral talks between the two countries lasted for three days.
3. The bilateral trade agreement was a major step forward in their relations.
4. Bilateral symmetry is a characteristic of most animals.
5. The bilateral hearing loss was caused by a congenital disorder.