Tear in to put back and stumble (4,2)
I believe the answer is:
trip up
'stumble' is the definition.
(synonyms)
'tear in to put back' is the wordplay.
'tear in' becomes 'ripup' (ripping up is a kind of tearing. I am not sure about the 'in' bit.).
'to' means one lot of letters go next to another (I've seen this in other clues).
'back' suggests the final letters (the letter at the back).
The final letter of 'put' is 't'.
'ripup' put after 't' is 'TRIP UP'.
'and' is the link.
Can you help me to learn more?
(Other definitions for trip up that I've seen before include "Cause person to stumble, or detect in error" , "'Cause to stumble (4,2)'" , "Go wrong" , "Catch out or cause to stumble" , "fluff" .)