Algoid is an adjective that describes something that is similar to or resembling algae. If you are looking for synonyms for this word, you might consider using the terms algae-like, seaweed-like, mossy, or lichenous. Other alternatives could include weed-like, fungal, microbial, or slimy. All these words suggest a similarity to algae, either in appearance, texture, or behavior. Depending on the context, some of these synonyms might be more appropriate than others. For instance, "seaweed-like" might be a better fit for things that grow in water, while "mossy" could be more relevant for things that grow on rocks or trees.