महाभारतः mahābhārataḥ - book-8, chapter-63, verse-54

नरनारायणावेतौ पुराणावृषिसत्तमौ ।
अनियत्तौ नियन्तारावभीतौ स्म परंतपौ ॥५४॥

54. naranārāyaṇāvetau purāṇāvṛṣisattamau ,
aniyattau niyantārāvabhītau sma paraṁtapau.

54. naranārāyaṇau etau purāṇau ṛṣisattamau
aniyattau niyantārau abhītau sma paraṃtapau

54. etau naranārāyaṇau purāṇau ṛṣisattamau
aniyattau niyantārau abhītau paraṃtapau sma

54. These two, Nara and Narayana, are the ancient and foremost among sages. They are unrestrained yet ultimate controllers, fearless, and tormentors of enemies.

Words meanings summery:

• नरनारायणौ (naranārāyaṇau) - Referring to Arjuna (Nara) and Krishna (Narayana) (Nara and Narayana)

• एतौ (etau) - these two

• पुराणौ (purāṇau) - two ancient ones, primeval

• ऋषिसत्तमौ (ṛṣisattamau) - two best among sages, foremost sages

• अनियत्तौ (aniyattau) - two unrestrained ones, uncontrolled

• नियन्तारौ (niyantārau) - two controllers, regulators

• अभीतौ (abhītau) - two fearless ones

• स्म (sma) - indeed, (particle indicating past tense with present verbs)

• परंतपौ (paraṁtapau) - two tormentors of enemies

Words meanings and morphology

नरनारायणौ (naranārāyaṇau) - Referring to Arjuna (Nara) and Krishna (Narayana) (Nara and Narayana)

(proper noun)

Nominative, masculine, dual of naranārāyaṇa

naranārāyaṇa - Nara and Narayana (a pair of ancient sages or divine beings)

Compound type : dvandva (nara+nārāyaṇa)

• nara – man, human being, Arjuna
  noun (masculine)
• nārāyaṇa – Narayana (a name of Vishnu/Krishna), resting on the waters
  proper noun (masculine)

एतौ (etau) - these two

(pronoun)

Nominative, masculine, dual of etas

etas - this, these

पुराणौ (purāṇau) - two ancient ones, primeval

(adjective)

Nominative, masculine, dual of purāṇa

purāṇa - ancient, old, primeval; an ancient narrative (Purāṇa)

ऋषिसत्तमौ (ṛṣisattamau) - two best among sages, foremost sages

(noun)

Nominative, masculine, dual of ṛṣisattama

ṛṣisattama - best of sages, foremost sage

Compound type : tatpuruṣa (ṛṣi+sattama)

• ṛṣi – sage, seer, inspired poet
  noun (masculine)
• sattama – best, most excellent
  adjective (masculine)
  Superlative degree from sat (good)

अनियत्तौ (aniyattau) - two unrestrained ones, uncontrolled

(adjective)

Nominative, masculine, dual of aniyata

aniyata - unrestrained, uncontrolled, unfixed, irregular

Negative of niyata (Past Passive Participle of ni-yam)

Compound type : nañ-tatpuruṣa (a+niyata)

• a – not, non-
  indeclinable
• niyata – restrained, controlled, fixed, regular
  adjective (masculine)
  Past Passive Participle
  From root yam with prefix ni
  Prefix: ni
  Root: yam (class 1)

नियन्तारौ (niyantārau) - two controllers, regulators

(noun)

Nominative, masculine, dual of niyantṛ

niyantṛ - controller, guide, regulator, charioteer

Agent noun from root yam with prefix ni

Prefix: ni

Root: yam (class 1)

अभीतौ (abhītau) - two fearless ones

(adjective)

Nominative, masculine, dual of abhīta

abhīta - fearless, brave, intrepid

Negative of bhīta (Past Passive Participle of bhī)

Compound type : nañ-tatpuruṣa (a+bhīta)

• a – not, non-
  indeclinable
• bhīta – frightened, afraid
  adjective (masculine)
  Past Passive Participle
  From root bhī ('to fear')
  Root: bhī (class 3)

स्म (sma) - indeed, (particle indicating past tense with present verbs)

(indeclinable)

परंतपौ (paraṁtapau) - two tormentors of enemies

(noun)

Nominative, masculine, dual of paraṃtapa

paraṁtapa - tormentor of enemies, subduer of foes (often an epithet for heroes)

Compound type : bahuvrīhi / upapada-tatpuruṣa (param+tapa)

• param – other, hostile, supreme
  adjective (masculine)
• tapa – burning, tormenting, asceticism (tapas)
  noun (masculine)
  Agent noun
  From root tap ('to heat, to torment')
  Root: tap (class 1)