'potty-trained' originates from the English word 'potty,' which refers to a small toilet for children, combined with 'trained,' meaning having undergone training.

'Potty' evolved from the word 'pot,' referring to a container, and 'trained' from the Old French 'trainer,' meaning to drag or pull.

Initially, 'potty' referred to a small pot or container, but over time it evolved to mean a child's toilet, and 'trained' retained its meaning of having undergone training.