oxalic ‘a violently poisonous substance found in many plants’
Lexical development traced from the Tamil root:
F. oxalique ‘of or pertaining to sorrel’ < Lat. oxalis ‘sorrel’ < Gk. oxalis < oxys ‘sharp’ < awk < ak < Tamil akku
Other meaning: Medicine: it is used to designate a predisposition to oxaluria.