'modem-compatible' originates from the combination of 'modem' and 'compatible', where 'modem' refers to a device that modulates and demodulates signals for data transmission, and 'compatible' means capable of existing or working together without conflict.

The term 'modem-compatible' evolved from the increasing need for devices and software to work seamlessly with modems, especially during the rise of internet connectivity.

Initially, it meant 'able to work with modems', and this meaning has largely remained the same in modern usage.