'shield on' is not correct or usable in written English.
You could say something like, "I put my shield up to protect myself."
Genesis has been moving in tandem with the Earth outside its magnetic shield on three orbits of the sun.
Simple: "A gun one side, a shield on the other".
If you have one, put a face shield on the baby to prevent the exchange of bodily fluids.
"Chief Thomas Cahill pinned the shield on me.
The shield on these loans is called a safe harbor.
"The Lord is thy shield on thy right hand".
Manchester United won the Community Shield on Sunday, but it's always winning something.
Tevez, 27, missed his side's 3-2 loss to former club Manchester United in the Community Shield on Sunday.
Mobile carrier Docomo is already offering the NEC N-03B, a feature phone using Scratch Shield, on the Japanese market.
After watching Manchester United beat Manchester City in the Community Shield on Sunday, I would make Sir Alex Ferguson's side huge favourites for the Premier League title.
Yet it also assisted the Turkish-led rebel offensive on Jarabulus, dubbed "Operation Euphrates Shield," on Wednesday.
