1Burning; combustion — the chemical process of oxidation that produces fire or the act of burning.
燃焼効率を高めるために空気の供給量を調整する。
Adjust the air supply to improve combustion efficiency.
不完全燃焼は一酸化炭素の発生を招く。
Incomplete combustion leads to the production of carbon monoxide.
キャンプでは燃焼中の火から目を離さないでください。
At a camp, do not take your eyes off a burning fire.
2Figuratively, to apply oneself with full energy or passion — giving one's all (often used as 'to burn with enthusiasm').
彼はプロジェクトに燃焼し、夜遅くまで働いた。
He threw himself into the project and worked late into the night.
若い選手たちは燃焼するような闘志を見せた。
The young players showed a burning fighting spirit.
燃焼し尽くすような集中力で試験に臨んだ。
I approached the exam with a focus as if burning out completely.