Set sth/sb on fire: If you set fire to something or if you set it on fire, you start it burning in order to damage or destroy it. : 1-A peace activist had set herself on fireएक शांति कार्यकर्ता ने खुद को आग लगा ली थी. 2-They set fire to vehicles outside that building उन्होंने उस इमारत के बाहर खड़े वाहनों में आग लगा दी. 3-Lightning set several buildings on fire बिजली गिरने से कई इमारतों में आग लग गई।. Set someone or something free (from something): To liberate someone or something from imprisonment or confinement. 1-The birds were set free. 2-After three years the prisoner was set free.