Related Clues:

• Member of a fighting force
• Sounds as if that's for the girl, so it sounds lively
• One might have to fight to get into something for the plumber
• One is fighting to get into what the plumber uses
• I am for fighting in what's of use to the plumber
• This is older than 13 across, for instance
• One comes to blows and gets paid for it
• Sounds as if I got some money from you for the mercenary
• Disposed of one with 'er in 2 down
• One serves in the army
• One has to join up without becoming a fighter
• Fighting man takes second right, holding magazine
• Joiner grabs first one in the army
• Join undercover unit as a fighter
• Join, in a way, when one gets admitted in private