We had an implicit agreement that we would support each other.

There are implicit elements.

In short, let it be your maxim through life to know all you can know, yourself; and never to trust implicitly to the information of others. This rule has been of infinite service to me in the course of my life.

That's implicit. You don't need to state it explicitly.

Mary, history says that the Roman Empire had bread and circuses for the masses, but really it was a vast conspiracy by the Roman oligarchy to change the very structure of Latin itself. By using a method of 'pronounic decoupling', the implicit mechanisms of Latin were disengaged and its speakers were hardly ever able to understand each other. And that's why I got drunk last night," said Tom.

Yanni trusted his co-worker implicitly.

Nothing appears more surprising to those, who consider human affairs with a philosophical eye, than the easiness with which the many are governed by the few; and the implicit submission, with which men resign their own sentiments and passions to those of their rulers.

Some implicit elements can be made explicit.