intelligent (having a high level of mental ability and being good at thinking clearly and understanding ideas): We have selected the most intelligent students. She is very intelligent.
clever (intelligent and quick at learning and doing things): Our children are all clever. Mike is quite clever.
smart US (clever): He is not as smart as his father.
bright (clever): He is a very bright child. This isn’t a very bright thing to do.
brilliant (very clever or highly skilled): He was a brilliant scientist. She has brilliant ideas.
canny (clever and able to think quickly): He is a canny lawyer.