* Decade: This word comes from the Greek word "dekas," meaning "ten." It refers to a period of ten years.
* December: This month's name comes from the Latin word "December," which itself comes from the phrase "decem," meaning "ten." In the ancient Roman calendar, December was the tenth month.
* Decimal: This term refers to a number system based on the number ten. It ultimately derives from the Latin word "decem," meaning "ten."
* Deci-: This prefix in the metric system means "one-tenth." It comes from the Latin word "decem," meaning "ten."
It's important to note that while "dec" is often used as an abbreviation for "decade" or "December," it can also be used in other contexts where it might stand for something else. To understand the origin of "dec" in a specific instance, you need to consider the context in which it is used.