-faction

The story

1. Latin · derived from-factiō
2. French · borrowed from-faction
3. English today-faction

Borrowed from French -faction, from Latin -factiō. This is the ending that arises when forming action nouns using -tiō (equivalent to English -tion) from compound verbs ending in -faciō (“to make, to do”), which carry a causative meaning. For example, liqueō (“to be liquid”) + faciō > liquefaciō (“to make (something) liquid”) > liquefactiō > English liquefaction. The suffix was later applied to other Latin stems where no Latin verb in -faciō existed (e.g. lubrifaction) and, eventually, even more freely (but see usage notes). Compare -ification and -ication.