Put down, then men raised mast on high (5)
I believe the answer is:
royal
'mast on high' is the definition.
'royal' can be an answer for 'mast' (royal mast is a kind of mast). I'm not sure about the 'on high' bit.
'put down then men raised' is the wordplay.
'put down' becomes 'lay' (lay something down).
'then' is a charade indicator (letters next to each other).
'men' becomes 'OR' (Other Ranks: non-commissioned soldiers).
'raised' is a reversal indicator (going up in a down clue).
'lay'+'or'='layor'
'layor' in reverse letter order is 'ROYAL'.
Can you help me to learn more?
(Other definitions for royal that I've seen before include "- Icing, - flush, - jelly" , "Queen Mary, for example" , "Of queens, say" , "Magnificent" , "Relating to king/queen" .)