'stain-prone' is a compound word formed from 'stain' and 'prone', where 'stain' refers to a mark or discoloration and 'prone' means likely to suffer from or experience something.

The word 'stain' comes from the Old Norse word 'steina', meaning 'to paint'. 'Prone' originates from the Latin word 'pronus', meaning 'leaning forward'.

Initially, 'prone' meant 'leaning forward', but over time it evolved to mean 'likely to experience'.