Monarch capturing small-time cattle thief? (7)
I believe the answer is:
rustler
'cattle thief?' is the definition.
(synonyms)
'monarch capturing small-time' is the wordplay.
'monarch' becomes 'ruler' (I've seen this in another clue).
'capturing' indicates putting letters inside.
'small' becomes 's' (abbreviation - e.g. clothes size).
'time' becomes 't' (abbreviation).
's'+'t'='st'
'ruler' placed around 'st' is 'RUSTLER'.
(Other definitions for rustler that I've seen before include "Cattle-robber" , "Cattle stealer" , "Stock taker?" , "one whose stock-taking is dishonest" , "Cattle thief" .)