What does 海路 mean?
海路 is a Japanese noun meaning “sea route” in English. It is written as 海路 in kanji, かいろ in hiragana, and kairo in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
陸路を運ぶのは大変ですが、海路で運ぶのは簡単です。
It's very difficult to transport them overland, but simple to do so by sea.