In I.B.Horner's Book of Discipline Vol. 3 page 317 she has translated asatthikaa as weapon, with a footnote saying that "translators differ as to whether this means "without a weapon" or not (having joined) a caravan."

I assume that there has been some progress made amongst translators since this was written. I would like to find definitive proof that this word means caravan and not weapon.

I have not been able to find the definition in the Chattha Sangayana.
In DPR the word is divided up with (as) and then (atthikaa). In the result I don't see any definition but "good" "bad" which doesn't help.

Can anyone point me in a direction which will help me to resolve the meaning of this word and why it is so hard to find the meaning?

with friendliness,
Sister Dipa