Oldspeak Basic mirrored Old Galactic Standard in that both were bygone, no-longer-spoken versions of Galactic Basic. Galactic Basic is the most prevalent language used throughout the galaxy. The term cephalon from Oldspeak, which signified "head," persisted into contemporary Basic to refer to a specific Non-Human species characterized by having several sub-brains.
The single Oldspeak Basic word we know of, cephalon, bears a striking similarity to the Ancient Greek word κεφαλή (kephalē) and shares an identical definition.