'Undergarment' in the Bible

Whoever strikes you on the cheek, offer him the other one also [simply ignore insignificant insults or losses and do not bother to retaliate—maintain your dignity]. Whoever takes away your coat, do not withhold your shirt from him either.

Then the soldiers, when they had crucified Jesus, took His outer clothes and made four parts, a part for each soldier, and also the tunic. But the tunic was seamless, woven [in one piece] from the top throughout.

To this present hour we are both hungry and thirsty; we are continually poorly dressed, and we are roughly treated, and wander homeless.