Soldiers on, breaching target over railroad (8)
I believe the answer is:
military
'target over railroad' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'soldiers on breaching' is the wordplay.
I cannot quite see how this works, but
'soldiers' could be 'ta' (abbreviation for Territorial Army) and 'ta' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for military that I've seen before include "Relating to armed forces" , "in the field" , "Related to soldiering" , "Of soldiers and warfare" , "Relating to the army" .)