* ἀλήθεια (alētheia): This is the most common and generally accepted translation. It emphasizes the unveiling of what is hidden, the disclosure of reality, and the opposite of falsehood. It carries a strong philosophical weight and is often used in contexts relating to metaphysical truth or honesty.
* ἀλήθης (alēthēs): This is the adjective form of ἀλήθεια, meaning "true" or "truthful." You'd use this to describe something *that is* true, rather than the abstract concept of truth itself.
* ὄρθος (orthos): This word means "straight," "right," or "correct." It can be used to describe something that is true in a moral or factual sense, particularly in the sense of being correct or proper.
Therefore, depending on the context, ἀλήθεια (alētheia) is usually the best choice, but ἀλήθης (alēthēs) and ὄρθος (orthos) can be appropriate alternatives.