General synonyms:
* Sagacious
* Prudent
* Judicious
* Discerning
* Insightful
* Perceptive
* Astute
* Intelligent
* Sensible
* Clever
More specific synonyms:
* Sage: (implies deep wisdom gained through experience)
* Learned: (implies extensive knowledge)
* Sophisticated: (implies worldly experience and refined judgment)
* Enlightened: (implies a higher understanding and awareness)
* Knowledgeable: (implies a broad range of information)
* Experienced: (implies practical wisdom gained through time)
* Shrewd: (implies practical wisdom and cunning)
Informal synonyms:
* Smart
* Brilliant
* Sharp
* Cunning
The best synonym will depend on the specific context of your sentence.