What about femora? Femora is incorrectly used as a word for female, when in reality:
Femur
plural noun: femora
1. the bone of the thigh or upper hind limb, articulating at the hip and the knee.
2. the third segment of the leg in insects and some other arthropods, typically the longest and thickest segment.
In reality, femora is the plural for femur. :/