flatfeet
nounUK /ˌflætˈfiːt/
US /ˌflætˈfiːt/
Flatfeet means the bottom of your feet is flat instead of curved.
He has flatfeet, so he needs special shoes.
OTHER MEANINGS
2. A condition where the arch of the foot is very low or missing.
The doctor said her flatfeet were causing knee pain.
3. A person's feet that lie flat on the ground without a normal arch.
Running long distances is harder for people with flatfeet.
4. Informal term for feet that look wide and flat.
He joked that his flatfeet made him a slow swimmer.