The temple garment (formally the "Garment of the Holy Priesthood" or informally, "the garment") is a set of special underwear worn by Mormons who have taken part in the endowment ceremony in a Mormon temple.
Latter-day Saints who have been endowed in the temple are expected to wear the garment under their clothes every day and night. They are commonly clothed in the temple garment and the outer temple clothing for burial.
The temple garment is similar for men and women. Both are white and consist of a T-shirt-like top with short sleeves and shorts that end just above the knee.
The Mormon temple garment symbolizes the "coats of skins" that God made for Adam and Eve before casting them out of the Garden of Eden (Gen. 3:21).
It is a reminder of special promises or covenants to God.
On a practical level, the garment also serves as a guide to modest dressing — a woman could hardly wear a tank top and a miniskirt while wearing the temple garment, nor could a man go publicly shirtless.
Spiritually, the garment is believed to be a "shield and protection" against the powers of evil (and sometimes against physical harm, according to some Latter-Day Saints).
The Mormon temple garment is considered sacred. It may not be publicly displayed and is considered impolite and irreverant to discuss it.