Box
counter, noun, suffix
The kanji and the word are exactly the same. That means they share meanings as well.
The reading is the same as the one you learned with the kanji.
この箱、重いから気をつけてね。
Be careful with this box; it's heavy.
このダンボール箱には、いらなくなった服が入っています。
This cardboard box contains unwanted clothes.
夫がトマトを箱で買ってきて、食べきれなくてこまっています。
My husband bought a box of tomatoes, and we are struggling to finish them.