Shield
The kanji and the word are exactly the same. That means they share meanings as well.
たて
Think of a big ol' shield. It's so big it will stand (立て) tall right in front of you.
盾を買いたいんだけど、どこに行けば買えるのか知りませんか？
I want to buy a shield, do you know where I can go to buy one?