principal
capital (principal)
the original amount of money saved, invested or borrowed, not counting interest.
Example
If you borrow $5,000 for a car and repay $5,600, the principal is $5,000 and the interest is $600.
In Spanish
capital (principal) — la cantidad original de dinero que se ahorra, se invierte o se pide prestada, sin contar el interés.
Si pides prestados $5,000 para un carro y devuelves $5,600, el capital es $5,000 y el interés es $600.