It's possible you are thinking of "Deca-" which is a Greek prefix meaning "ten".
For example:
* Decagon: A polygon with ten sides.
* Decameter: A unit of length equal to ten meters.
* Decalogue: The Ten Commandments.
Decca is actually a brand name, not a Greek prefix. It was originally used for a system of long-range radio navigation and later became associated with record labels and radio stations.