Hi Fearn
About the falx, maybe i didn't express as i wished. Naturally the falx=fouce is basicaly a tool, later "improved" for weaponry. The anatomy aproach was because i couldn't yet figure out whether was the so called brain structure shape that gave the name to the tool, or vice versa.
About people's broad or keen definition of either tools/weapons and objective weapons, i was considering that, in old days, the tools were the optional ( available ) weapons, therefore the little existance of old weapons names based on their unique lethal purpose like, as you remind, the Gladius adopted by Romans.
fernando
By the way
http://psychcentral.com/psypsych/Dagger