refers to the needle, the whole things should read staked needles prefilled syringe. Staked here meaning glued-in.
Here is a nice explanation:
Prefilled Syringe Components
Prefilled syringe (PFS) components consist typically of a glass syringe barrel, having a Luer finish or staked (glued-in) needle, an elastomeric tip closure, an elastomeric plunger-stopper, and a plunger rod (see Figure 1). The labeled syringe may also be equipped with an external anti-needle-stick safety device and/or packaged in a thermoformed tray.
http://www.americanpharmaceuticalreview.com/ViewArticle.aspx...