Turn up with two Frenchmen at the Spanish strike (6)
I believe the answer is:
pummel
'strike' is the definition.
(thesaurus)
'turn up with two frenchmen at the spanish' is the wordplay.
'turn' is a reversal indicator.
'with' is a charade indicator (letters next to each other).
'two frenchmen' becomes 'MM' (two M's - M is short for Monsieur).
'at' says to put letters next to each other.
'the spanish' becomes 'el' ('the' in Spanish).
'up' backwards is 'pu'.
'pu'+'mm'+'el'='PUMMEL'
(Other definitions for pummel that I've seen before include "Keep thumping" , "Strike repeatedly with the fists" , "Beat with a flurry of punches" , "Hit repeatedly with fists" , "Batter" .)