Om tryambakam yajaamahe sugandhim pushti-vardhanam
urvaarukam iva bandhanaan mrityormukshiiya maamritaat
This mantra is dedicated to Rudra as Mrityunjaya and found in the Rig Veda.
It is called the Maha Mrityunjaya mantra (the Great Death-Conquering mantra), Rudra mantra (referring to the furious aspect of Shiva), the Tryambakam mantra (alluding to Shiva's three eyes) and it is sometimes known as the Mrita-Sanjivini mantra (because it is a component of the "life-restoring" practice given to the primordial sage Shukra after he had completed an exhausting period of austerity).
The Maha Mrityunjaya mantra is hailed by the sages as the heart of the Veda. Along with the Gayatri mantra it holds the highest place among the many mantras used for contemplation and meditation
Word to Word Meaning of Maha Mrityunjaya Mantra
aum = is a sacred/mystical syllable
tryambakam = the three-eyed one (accusative case)
yajaamahe = we worship, adore, honor, revere
sugandhim = sweet smelling, fragrant (accusative case)
pushti = a well-nourished condition, thriving, prosperous, fullness of life
vardhanam = One who nourishes, strengthens, causes to increase (in health, wealth, well-being); who gladdens, exhilarates, and restores health; a good gardener
urvaarukam = 'urva' means "vishal" or big and powerful or deadly. 'arukam' means 'disease'. Thus urvaarukam means deadly and overpowering diseases. The diseases are also of three kinds caused by the influence (in the negative) of the three gunas and are ignorance (avidyaa), falsehood (asat, as even though Vishnu is everywhere, we fail to perceive Him and are guided by our sight and other senses) and weaknesses (shadripu, a constraint of this physical body and Shiva is all powerful).
iva = like, just as
bandhanaan = "from captivity" bandhanaan means bound down. Thus read with urvaarukam iva, it means 'I am bound down just as by deadly and overpowering diseases'.
mrityor = from death
mukshiiya= free, liberate
maa = me
amritaat = [with] immortality, emancipation
Three-eyed one, I meditate on you, who increase fragrance and nourishment. From powerful disease, bondage and death free us into immortality.
Though the mantras generally start with word OM, one should end it also with word OM.
According to some puranas, the mahamrutyunjaya mantra has been used by many rishis as well as Sati during the time when Chandra suffered from the curse of Prajapati Daksha. By reciting this mantra, the effect of the curse of Daksha, that could make him die, slowed, and Shiva then took Chandrama on his head.
Text and explanation from