Definitions of alga
  1. noun
    primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves
    synonyms: algae
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    plant growing in the sea, especially marine algae
    golden algae
    algae having the pigments chlorophyll and carotene and xanthophyll
    yellow-green algae
    any alga of the division Chrysophyta with its chlorophyll masked by yellow pigment
    microscopic unicellular marine or freshwater colonial alga having cell walls impregnated with silica
    confervoid algae
    algae resembling confervae especially in having branching filaments
    brown algae
    algae having the chlorophyll masked by brown and yellow pigments
    euglenid, euglenoid, euglenophyte
    marine and freshwater green or colorless flagellate organism
    chlorophyte, green algae
    algae that are clear green in color; often growing on wet ricks or damp wood or the surface of stagnant water
    any alga of the genus Chlorella
    red algae
    marine algae in which the chlorophyll is masked by a red or purplish pigment; source of agar and carrageenan
    cryptomonad, cryptophyte
    common in fresh and salt water appearing along the shore as algal blooms
    an edible seaweed with a mild flavor
    dried seaweed especially that cast ashore
    any of various seaweeds that grow underwater in shallow beds
    sea wrack, wrack
    growth of marine vegetation especially of the large forms such as rockweeds and kelp
    any of various algae of the genus Tribonema; algae with branching filaments that form scum in still or stagnant fresh water
    large brown seaweeds having fluted leathery fronds
    sea tang, tang
    any of various coarse seaweeds
    fucoid, fucoid algae
    any of various algae of the family Fucaceae
    coarse brown seaweed growing on rocks exposed at low tide
    Fucus serratus, serrated wrack, tang
    brown algae seaweed with serrated edges
    Sargassum bacciferum, gulfweed, sargasso, sargassum
    brown algae with rounded bladders forming dense floating masses in tropical Atlantic waters as in the Sargasso Sea
    laver, sea lettuce
    seaweed with edible translucent crinkly green fronds
    pond scum
    free-floating freshwater green algae
    freshwater algae consisting of minute filaments containing spiral chlorophyll bands
    any of various submerged aquatic algae of the genus Chara having nodes with whorled filamentlike branches; usually encrusted with calcium carbonate deposits
    freshwater green algae
    sea moss
    any of various red algae having graceful rose to purple fronds (e.g. dulse or carrageen)
    Chondrus crispus, Irish moss, carageen, carrageen, carragheen
    dark purple edible seaweed of the Atlantic coasts of Europe and North America
    Rhodymenia palmata, dulse
    coarse edible red seaweed
    laver, red laver
    edible red seaweeds
    type of:
    any of the unicellular protists
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