* Chronology: The order in which events happen in time.
* Chronicle: A record of events in the order they happened in time.
* Chronic: Something that lasts for a long time, or is persistent over time.
* Chronogram: A message or inscription where the date is encoded by the numerical value of the letters, using their position in time.
In each case, "chron" emphasizes the temporal aspect of the word. It helps us understand that the words are all related to the concept of time and its passage.