A slip made by the novice in the team (5)
I believe the answer is:
slide
'a slip' is the definition.
(I know that slip can be written as slide)
'the novice in the team' is the wordplay.
'the novice' becomes 'l' (as in a learner driver with L-plates on their car).
'in the' means one lot of letters goes inside another.
'team' becomes 'side' (both can mean a sports team).
'l' placed inside 'side' is 'SLIDE'.
'made by' acts as a link.
(Other definitions for slide that I've seen before include "Playground item" , "that's put under the microscope" , "Microscope glass" , "Make mild fun of" , "Playground structure" .)