To bury the hatchet

This comes from the American custom of burying hawks and other weapons as a sign that hostilities between the American Indians and the White had ended. Nowadays, this idiom is used to refer to coming to peaceful terms with an opponent.

Custom = costumbre

To bury = enterrar

Hawk = hacha

Weapons = armas

Sign = símbolo, señal

To come to peaceful terms = hacer las paces

Opponent = enemigo, contrario

A white elephant

White elephants, also known as albino elephants, were considered holy in ancient times, specially in some Asian countries. To keep these animals was very expensive, because it was necessary to give them special food, and also to give access to the people who wanted to worship them. In Thailand, if a king was dissatisfied with someone, he would give him a white elephant, which would surely make that person lose all his money. Nowadays, this expression is used to refer to something that costs a lot of money to maintain but is useless.

Holy = sagrado
Ancient times = antiguamente
To keep = mantener
To worship = adorar
Dissatisfied = insatisfecho
Surely = seguramente
To lose = perder
To maintain = mantener
Useless = inútil