Glochidium is a term often used to describe tiny barbed or spiny structures found on the surface of various plants and animals. These structures may be used for defensive purposes or as a way of clinging onto surfaces. Synonyms for glochidium may include terms like thorn, spine, barb, prickle, spike, or prickly appendage. Other related terms may include bristle, needle, hook, or point. Depending on the context, these synonyms may be used interchangeably and can help to add depth and nuance to descriptions of various organisms and their features.