Filicopsida is a scientific term commonly used in the field of biology to refer to fern plants. Though it is a specific term, there are several synonymous terms that can be used interchangeably, such as Filicinae, Polypodiopsida, and leptosporangiate ferns. It is widely known that ferns are primitive, flowerless plants that produce spores for reproduction. The term Filicinae is derived from filicis, a Latin word which means 'fern,' and is used to differentiate fern plants from other plants. Similarly, Polypodiopsida, which refers to a class of ferns, literally means 'many-footed ferns.' These synonyms help researchers and students to better understand and communicate about these fascinating plants.