Other forms: raincoats
A raincoat is the waterproof coat you wear when it is raining. A yellow raincoat, put on a raincoat, a light raincoat.
Being waterproof and being breathable pull against each other, which is the whole problem of the garment: a fully sealed raincoat leaves you wet from the inside. Modern membranes let vapour out and keep drops out, imperfectly.
1nounraincoatA waterproof coat worn against the rain.
“Take a raincoat; the forecast says it'll pour all afternoon.”
raincoat is a garment.
From rain + coat.
Etymology from Wiktionary, CC BY-SA