Undergarment (noun)

1. Clothes worn next to the skin and under other clothes.
2. An article of clothing worn under outer clothes, especially to provide a foundation for other clothing.

Origin:

Late middle english: from under + garment.

Examples:

1. She chose a comfortable cotton undergarment for her long flight.
2. He preferred to wear a tank top as an undergarment.
3. The undergarment was the first thing she put on in the morning.
4. The undergarment was an important part of a woman's wardrobe.
5. The undergarment was designed to be worn discreetly.