To Run Alongside, To Run Parallel To
godan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means run alongside so the verb vocab version is to run alongside.
そう
Imagine yourself on a path designed to run alongside an endless array of soap (そ) bars. As you walk alongside the soap bars, you enjoy their delightful scents. It's a "scent-sational" promenade with soap bars that leaves you feeling squeaky clean!
川の両岸に沿って、ずうっと、美しい桜並木があるんです。
There are beautiful cherry blossom trees all along the river banks.