A brick — a hardened block of clay or similar material used in building and paving. Often written in kana as 'レンガ'.
古い倉庫は赤い煉瓦でできている。
The old warehouse is made of red bricks.
庭の小道にレンガを敷いた。
I paved the garden path with bricks.
煉瓦塀の前で写真を撮った。
We took a picture in front of the brick wall.