1) Like algae 2) Like an aquarium growth 3) Of a seaweed 4) Of or resembling algae 5) Protoctist 
• (a.) Of the nature of, or resembling, an alga.
Al'goid adjective [ Latin alga + - oid .] Of the nature of, or resembling, an alga. 
[adj] - of or resembling algae
algoid Resembling, or of the nature of seaweed.
adjective of or resembling algae
like algae.