There are not many synonyms for the word "tetraspore", which refers to a type of spore produced by some algae. However, there are related words that can be used in its place, such as "tetrasporangium" (the structure that produces tetraspores), "tetrasporophyte" (the stage of the life cycle where tetraspores are produced), or simply "spore" (a more general term for reproductive cells produced by plants and algae). In scientific writing, it is important to use the correct terminology to accurately describe and understand the organism or process being studied.