Initial pile-up called minor accident (5)
I believe the answer is:
prang
'minor accident' is the definition.
(I've seen this before)
'initial pile-up called' is the wordplay.
'initial' suggests taking the first letters.
'up called' becomes 'rang' ('ring' can be a synonym of 'call'. I am not sure about the 'up' bit.).
The first letter of 'pile' is 'p'.
'p'+'rang'='PRANG'
Can you help me to learn more?
(Other definitions for prang that I've seen before include "Car accident, usually not too serious" , "Plane or car crash" , "Car collision" , "Possible argument with van" , "Crash (slang)" .)