Very pleased to have been of help - I've just found a few more alternative spellings:
"Catty" we use comes from the Tamil "Katthi" - a knife or billhook - see:
http://www.infolanka.com/org/srilanka/cult/38.htm
Also 'ketha' see:
http://groups.yahoo.com/group/srilan...s/message/3739
In southern India the local name for a billhook is 'kandali' in the kannada language - which I guess may have the same etymological roots
see:
http://books.google.fr/books?id=E1C3...page&q&f=false
Once you start searching the www it is difficult to stop...