No definitions found for 'nirvana principle'
Perhaps one of these:
nirvana,
nerving,
norepinephrine,
nerve end,
noropianic,
narvon,
narrow pennant,
nerve ending,
narrowband,
nervomuscular,
nirvanic,
nerve entrapment,
nerve impulse,
nauropometer,
nervimotor,
nervimotion,
nervine