Clever student in Lincoln? (4)
I believe the answer is:
able
'clever' is the definition.
(able can mean skilled or talented)
'student in lincoln?' is the wordplay.
'student' becomes 'l' (as in L-plates for learner drivers).
'in' indicates putting letters inside.
'lincoln?' becomes 'abe' (Abraham Lincoln).
'l' put within 'abe' is 'ABLE'.
(Other definitions for able that I've seen before include "Talented" , "As capable as a mariner" , "Bale out, being competent" , "Competent and fit, like sailor" , "Fit as a seaman" .)