Clever student in Lincoln? (4)
I believe the answer is:
able
'clever' is the definition.
(I've seen this before)
'student in lincoln?' is the wordplay.
'student' becomes 'l' (as in L-plates for learner drivers).
'in' means one lot of letters goes inside another.
'lincoln?' becomes 'abe'.
'l' put inside '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" .)