Troops attempt to secure serviceman's archive (8)
I believe the answer is:
registry
'archive' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'troops attempt to secure serviceman's' is the wordplay.
'troops' becomes 'RE' (Royal Engineers army regiment).
'attempt to' becomes 'try' (I've seen this in other clues).
'secure' indicates putting letters inside (inserted letters are secured inside).
'serviceman's' becomes 'gi's' (informal term for a US soldier).
're'+'try'='retry'
'retry' placed around 'gis' is 'REGISTRY'.
Can you help me to learn more?
(Other definitions for registry that I've seen before include "Place of record" , "Official written record of names, events etc" , "Place to keep records" , "record-holder" , "Place where written documents or records are kept" .)