A virtue that allows us to determine what's right and what's wrong, stop and consider the consequences of our decisions before acting or speaking and then act accordingly. Developing this virtue allows one to differentiate between right and wrong in situations where different values might collide or there are no clear guidelines.
Generally speaking, wisdom is a kind of moral insight. So it appears to be both a moral and intellectual virtue. For the wise person has knowledge of what is the best conduct in particular situations, and this knowledge is manifested in good conduct. So you might say that wisdom is a sort of "governing" virtue that is necessary to some degree, for the development of all oth r virtues.
Wisdom, in the ethical sense of the term, is a very different thing from book-learning. Illiterate people are frequently exceedingly wise while learned people are often the biggest fools. Wisdom is the sense of proportion - the power to see clearly one's ends, and their relative worth; to subordinate lower ends to higher without sacrificing the lower altogether; and to select the appropriate means to one's ends, taking just so much of the means as will best serve the ends - no more and no less. It is neither the gratification nor the suppression of appetite and passion as such, but the organization of them into a hierarchy of ends which they are sternly compelled to subserve.
It isn't enough to be intelligent or to think critically or even creatively - it's how you use the knowledge you have for the betterment of self, others and the world. Regardless of academic education or even age, people are wise if they use the knowledge they have at appropriate times, using proper judgment and discernment with good intentions.