Their homes are sheltered by the reef from wave action.
I can't grasp the meaning of the expresion!
"wave action" refers to the process by which waves erode the coast, or move material such as sand or shingle along the coast. The reef acts as a barrier, preventing the waves (or the big waves anyway) from reaching the area of the coast where their homes are situated and potentially causing damage.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
"wave action" refers to the process by which waves erode the coast, or move material such as sand or shingle along the coast. The reef acts as a barrier, preventing the waves (or the big waves anyway) from reaching the area of the coast where their homes are situated and potentially causing damage.