महामृत्युञ्जयमन्त्रः
Maha Mrityunjaya Mantra: Rig Veda Source and Meaning
Recited in worship of Shiva as Mrityunjaya, the Conqueror of Death. Modern guides (Shlokam.org) also describe chanting it on behalf of someone sick or close to death.
Rig Veda · 1 verse