Confident is an adjective

However, the adjective is often confused with the noun "confidant":  a close friend or associate to whom secrets are confided or with whom private matters and problems are discussed. Someone you trust and can share secrets with.

"Confident" is an adjective. "I am confident in the weather report that says today will be sunny." To be confident means to be certain.

"Confidence" is the corresponding noun. "I have confidence in the weather report."

Both of these words carry the sense of "certainty."

There are several other words that carry the sense of "trusting with secrets."

"To confide" is to trust someone with a secret. "If you are bothered by something, don't keep it to yourself. Find someone to confide in."

The person you confide in is your "confidant" (-ant, not -ent) or "confidante."

Something is "confidential" if it is a secret that should only be disclosed to someone trustworthy. "This is confidential, for your eyes only."