seaweed

/ˈsiˌwid/
noun
  1. Plants that grow in the sea or ocean, especially algae that are often green, brown, or red.
    • Seaweed is used in many foods, such as sushi rolls and salads.
    • Divers swam through a forest of tall seaweed near the rocky coast.
    • The beach was covered with seaweed that had washed ashore overnight.
Synonyms