Concentrate on central point (5)
I believe the answer is:
focus
I believe this is a double definition.
'concentrate' is the first definition.
('focus' can be a synonym of 'concentrate')
'central point' is the second definition.
(I've seen this before)
'on' acts as a link.
(Other definitions for focus that I've seen before include "Centre of interest or activity (5)" , "Spotlight" , "Central point" , "Adjust (camera lens)" , "Main topic of attention" .)