Coast, Seacoast
Noun and の adjective
かいがん
花火大会の日に、ゆかたをきて海岸ぞいを歩いているカップルを見るのがすきです。
I like seeing couples walk along the seashore in yukata on days when there are fireworks.
海岸にあるいいカフェを知ってるんだけど、よかったら一しょにお茶しない？
I know a good cafe at the coast. Do you wanna get tea with me?
「今日、私達と一緒に海岸に行かない？」「またの機会にするよ。」
"Do you want to go to the seashore with us today?" "I’ll take a rain check this time."
The ocean/sea coast is the seashore. Then again, it could also be the coast as well.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.