Torbk:
I like your axe-carrier.
The term Securifer (or Securiger) does refer to an axe carrier, but it is not the origin of the word Security. Security comes from Securitas, which means something metaphorically similar, and has the same sort of etymology as words like Liberty, Equality, and Fraternity (Libertas, Aequalitas, Fraternitas). This word is itself derived from the word Securus (Secure), which is a combination of a prefix meaning 'without' and the word for 'care'. In contrast, the word Securifer/Securiger derives from the word for Axe, Securis, which in turn derives from the word for 'cut', Seco, (Secare, Secui, Sectum).
If anyone requires work with Latin translations, I am happy to provide. Just be aware that I will probably not be around consistently.
-LM