* νοῦς (nous): This is probably the closest single word. It refers to mind, intellect, reason, and understanding – encompassing both intellectual capacity and intuition. It's often translated as "mind" or "intellect," but carries a stronger connotation of insightful understanding.
* φρόνησις (phronesis): This word signifies practical wisdom or prudence – the ability to make sound judgments in real-life situations. It's not just about raw intelligence, but the application of intelligence to ethical and practical matters.
* σοφία (sophia): This means wisdom, encompassing knowledge, understanding, and judgment, often gained through experience. It's a higher level of intellectual attainment than simply intelligence.
The best choice depends on the specific context. If you need a general term for cognitive ability, νοῦς (nous) is a strong contender. But if you're talking about practical intelligence or wisdom, φρόνησις (phronesis) or σοφία (sophia) might be more appropriate.