WordNet sense 1 (mentally quick and resourceful):

apt

WordNet sense 2 (having the capacity for thought and reason especially to a high degree):

intelligent

WordNet sense 3 (showing self-interest and shrewdness in dealing with others):

cagey, cagy, canny

WordNet sense 4 (showing mental alertness and calculation and resourcefulness):

smart

WordNet sense 5 (skillful (or showing skill) in adapting means to ends):

ingenious

WordNet sense 6 (showing inventiveness and skill):

cunning

WordNet sense 7 (quick or skillful or adept in action or thought):

adroit