combustion
‘act or process of burning’
Lexical development traced from the Tamil root:
O.F. combustion < Lat. combustionem ‘a burning’ < comburere ‘to burn up, consume’ < com + burere < amburere ‘to burn around’ < ambi-urere < urere ‘to burn, singe’ < uhs < heus- < Tamil uṇṇam
Other meanings: Pathology: inflammation; Astrology: obscuration of a planet or star by proximity to the sun.