* νοῦς (nous): This is probably the closest single word. It refers to the mind, intellect, reason, and understanding. It often implies a higher, intuitive form of understanding, almost akin to divine inspiration.
* διάνοια (dianoia): This word refers to the thinking process, reasoning, and mental activity. It's more focused on the process of intellectual activity than the abstract faculty itself.
* φρόνησις (phronesis): This translates to "practical wisdom" or "prudence." It emphasizes the application of intellect to ethical and practical situations.
* σύνεσις (synesis): This word signifies understanding, comprehension, and insight, often in a social or political context.
Therefore, the best translation of "intellect" in Greek depends heavily on context. νοῦς (nous) is generally a good starting point, but the others might be more appropriate depending on the specific shade of meaning you intend.