[baganing_balyan]

in addition:

It would be easy to assume that keris is from kilis and kilich, but i have no basis to base that from since I am not sure if ch can be s and L can be R in early languages of java and sumatra. One thing I am sure though is that kalimantan is not the same as karimantan.

if R and L can be interchangeably used, then I assume it is a later evolution as a linguistic pattern. since etymological analysis suggests that kalimantan is from kali-- not kari-- and mantan. there are no malay words such as kaliman, liman, and limantan, so liman cannot be a root word.

I do, however, use keras because its meanings symbolize the form and use of keris. Do I have a proof? Linguistic etymology or word relationship is my proof in the absence of texts and written history.

if later I find an evidence that indeed keris is from kilis/kilich, then keras, as a word, evolved from keris.

I just don't think that we cannot imply from a sound fact to reconstruct history.