After starting school, is able to read (4)
I believe the answer is:
scan
'read' is the definition.
(I know that read can be written as scan)
'after starting school is able to' is the wordplay.
'after' means one lot of letters go next to another.
'starting' says to take the initial letters.
'is able to' becomes 'can' (if you can do something you are able to do it).
The first letter of 'school' is 's'.
's' next to 'can' is 'SCAN'.
(Other definitions for scan that I've seen before include "View quickly" , "Survey - fit in metrically" , "show in this?" , "Run over" , "Glance at quickly rather than thoroughly" .)