Substitute about to get going (6,2)
I believe the answer is:
switch on
'get going' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how one could define the other.
'substitute about' is the wordplay.
'substitute' becomes 'switch' (I've seen this before).
'about' becomes 'on' (as in a book 'on' a certain topic).
'switch'+'on'='SWITCH ON'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for switch on that I've seen before include "trigger" , "start" , "Give power" , "Activate (equipment)" , "get to work" .)