indulto, m., pardon.
inefable, ineffable, unspeakable.
inexcusable, inexcusable.
inextinguible, inextinguishable.
infalible, sure, unfailing, infallible.
infame, infamous.
infancia, f., infancy, childhood.
infantil, infantine, childish.
infeliz, unhappy, unfortunate.
inferior, inferior, lower, less.