macroalga

noun

mac·​ro·​al·​ga ˌma-krō-ˈal-gə 

plural macroalgae ˌma-krō-ˈal-(ˌ)jē 

: a multicellular alga (such as rockweed or kelp) that is visible to the unaided eye

The New York State Department of Conservation has also received reports of various macroalgae (seaweed) and eelgrass washing up and decomposing along Long Island's shore.

—Nicole Fuentes

… an invasive brown macroalga that originates from Japan.

—James A. Strong et al.

compare microalga

Word History

Etymology

macro- + alga

First Known Use

1972, in the meaning defined above