combustion

noun
1
the process of burning
احتراق, سوختن, اشتعال
see also spontaneous combustion
2
a chemical process in which substances combine with the oxygen in the air to produce heat and light
احتراق, سوختن, احتراق شیمیایی, فرآیند شیمیایی سوختن
The ratio must be correct in order to achieve complete combustion.