"Sica" is a wellknown dacian word meaning sword, knife.
This is all we know about the meaning of this word. If there
should have been another meanings, there it is us at this
time, unknown.
I find very curious the latin cognate of this word:

latin sica= knife. ( I guess George has a fully definition of
the latin word sica )

Of course we can easy assume there is just a simple
coincidence, but again one?
The romanian language is of no help here. The word "secera" if
this is the one which evoluated from "sica" can in this case
be dacian or latin too.. It seems this is one of the words ,
we have to live with , and an "right" explanation about the
meaning of dacian "sica" and the form of both words in latin
and dacian, should be hard to find too...