Answer:
platonic acid (tentative) (the "(tentative)" is not part of the name btw)
Step-by-step explanation:
Usually, acids and their conjugated bases (their deprotonated form) follow the naming trend of "<something>-ic acid" and "<something>-ate"
For example, nitric acid goes with nitrate, perchloric acid goes with perchlorate, ect.
However, note that there are exceptions:
hypoiodic acid goes with hypoiodite, not hypoiodate
sulfuric acid goes with sulfate, not sulfurate
ect.
Following the rule that only sometimes works, the acid corresponding to platonate might be called platonic acid.