Antonyms for "Giant Platelet Syndrome" are relatively limited as it describes a rare genetic disorder affecting the blood's ability to clot normally. However, some possible opposites could include "healthy blood clotting," "normal platelet function," or "unaffected coagulation capabilities." These would describe the absence of the disorder's symptoms, which include abnormal bruising, nosebleeds, and excessive bleeding. In contrast, antonyms for "giant" and "platelet" could include words like "tiny," "microscopic," "reduced," or "diminished." However, these would not necessarily describe an opposite to the syndrome itself, but rather a difference in the size or quantity of blood components.