Seaweed, also known as ALGAE, is a type of PLANT that grows in the ocean. It is typically found in shallow waters and is composed of a variety of species. ALGAE, which is the most common type of seaweed, is a five-letter word for this term. PLANT is another five-letter word for seaweed, and ALGA is a four-letter word for it. Seaweed is an important part of the marine ecosystem, providing food and shelter for many aquatic creatures.