Thrombo-Embolic Deterrent socks... they are a form of support sock for people who can't get up and move well. Other types of compressive support socks are genenerically called TEDs. Since Hillary is moving, those are probably not real TEDs, but a compression sock to mitigate poor blood circulation.
Like blood tending to pool in the (c)ankles.
Thank you. I had not heard that term used for them before.