Pupils progressing together with speed get help completing circuit (9,4)
I believe the answer is:
crocodile clip
'help completing circuit' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'pupils progressing together with speed' is the wordplay.
I cannot really see how this works, but
'speed' could be 'clip' (I've seen this before) and 'clip' is found within the answer.
The remaining letters 'crocodile' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'get' acts as a link.
Can you help me to learn more?
(Other definitions for crocodile clip that I've seen before include "Temporary cable connector" , "one completing circuit?" .)