Your painting is recent and not taken from an historic reference dating before the Portuguese involvement.. Am I correct in assuming this?
Without wishing to get into a discussion long and difficult (impossible) about "whats in a word" I would caution that there is little evidence either way. I cannot see much of a tie up with your word association except that it is interesting.
Where I suggest a potential area of research which you may be better placed to identify is in the Martial Arts pre Portuguese weaponry style of swords used. The fact is that we are unable to identify an early enough Kastane (Kasthane) which would prove beyond doubt its earlier position.
The 16/17th century is too late....because;
Don Lourenšo de Almeida, son of the Portuguese viceroy in India, was sailing off the southwestern coast of Sri Lanka looking for Moorish ships to attack when stormy weather forced his fleet to dock at Galle. The rest as we say is history.
Ibrahiim al Balooshi.