Study after initially taking walk (5)
I believe the answer is:
tread
'walk' is the definition.
(I know that tread is a more specific form of the action the walk)
'study after initially taking' is the wordplay.
'study' becomes 'read' (synonyms).
'after' means one lot of letters go next to another.
'initially' indicates taking the first letters.
The initial letter of 'taking' is 't'.
'read' put after 't' is 'TREAD'.
(Other definitions for tread that I've seen before include "Walk along" , "Put one's foot down!" , "Walk or step like pattern on tyre" , "Walk; part of tyre" , "Grooved surface of a tyre" .)