along a rocky beach; along the shore
Describes moving or being situated along a rocky seashore. Often used with verbs of motion like 歩く or 行く.
We walked along the rocky beach to a small cove.
Compound of 磯 (いそ, 'rocky beach') and 伝い (づたい, 'along'). The reading づたい is a rendaku form of つたい.