Not you seartching this up
I am not very smart.... And neither are you
Something well suited to its purposes
Someone good at creating/doing things well suited to their purposes.
(Purpose: the reason for which something is done or created or for which something exists.)
This definition of smart is smart because it makes good contextual sense.
Someone who procrastinates and leaves projects and test studies for the last minute, but then magically turns on 120% of their brain power to get everything done on time and gets away with it because they still manage to get good grades somehow.
Adult: "What a smart and gifted child you are!"
Child: "Uhh, sure... Thanks!" 😅