महाभारतः mahābhārataḥ - book-8, chapter-55, verse-42

क्षणेन पुरुषव्याघ्रः प्रावर्तयत निम्नगाम् ।
यथा वैतरणीमुग्रां दुस्तरामकृतात्मभिः ॥४२॥

42. kṣaṇena puruṣavyāghraḥ prāvartayata nimnagām ,
yathā vaitaraṇīmugrāṁ dustarāmakṛtātmabhiḥ.

42. kṣaṇena puruṣavyāghraḥ prāvartayata nimnagām
yathā vaitaraṇīm ugrām dustarām akṛtātmabhiḥ

42. puruṣavyāghraḥ kṣaṇena nimnagām prāvartayata
yathā ugrām dustarām akṛtātmabhiḥ vaitaraṇīm

42. In an instant, that tiger among men (Bhīmasena) caused a river to flow, just like the formidable Vaitaraṇī, which is difficult for those lacking self-discipline (akṛtātman) to cross.

Words meanings summery:

• क्षणेन (kṣaṇena) - in a moment, instantly, quickly

• पुरुषव्याघ्रः (puruṣavyāghraḥ) - Bhīmasena, who is referred to as a 'tiger among men' (tiger among men, best of men)

• प्रावर्तयत (prāvartayata) - he caused to flow, he created, he set in motion

• निम्नगाम् (nimnagām) - a river

• यथा (yathā) - as, just as, like, in which way

• वैतरणीम् (vaitaraṇīm) - the Vaitaraṇī (river of hell)

• उग्राम् (ugrām) - fierce, formidable, terrible

• दुस्तराम् (dustarām) - difficult to cross, hard to overcome

• अकृतात्मभिः (akṛtātmabhiḥ) - by those whose souls are not prepared, by the unprepared, by those lacking self-discipline

Words meanings and morphology

क्षणेन (kṣaṇena) - in a moment, instantly, quickly

(noun)

Instrumental, masculine, singular of kṣaṇa

kṣaṇa - a moment, an instant, a twinkling of an eye, a very short space of time, leisure, opportunity

पुरुषव्याघ्रः (puruṣavyāghraḥ) - Bhīmasena, who is referred to as a 'tiger among men' (tiger among men, best of men)

(noun)

Nominative, masculine, singular of puruṣavyāghra

puruṣavyāghra - a tiger among men, an eminent man, a chief, a hero

Compound (tatpuruṣa or karmadhāraya, often treated as upamānaloka compound)

Compound type : tatpuruṣa (puruṣa+vyāghra)

• puruṣa – a man, a male, a human being, a person; the cosmic person (puruṣa)
  noun (masculine)
• vyāghra – a tiger
  noun (masculine)

प्रावर्तयत (prāvartayata) - he caused to flow, he created, he set in motion

(verb)

3rd person , singular, active, imperfect (laṅ) of vṛt

causative

root 'vṛt' with upasarga 'pra' and causative suffix -aya

Prefix: pra

Root: vṛt (class 1)

निम्नगाम् (nimnagām) - a river

(noun)

Accusative, feminine, singular of nimnagā

nimnagā - a river (literally 'that which goes down')

From nimna (down, low) + ga (going)

Compound type : tatpuruṣa (nimna+ga)

• nimna – low, deep, sunk, depressed
  adjective
• ga – going, moving, reaching; that which goes
  adjective
  agent noun from root gam
  Suffix -a from root gam
  Root: gam (class 1)

यथा (yathā) - as, just as, like, in which way

(indeclinable)

वैतरणीम् (vaitaraṇīm) - the Vaitaraṇī (river of hell)

(proper noun)

Accusative, feminine, singular of vaitaraṇī

vaitaraṇī - the river Vaitaraṇī (the mythological river separating the earthly world from the infernal regions)

From vi-taraṇa (crossing over)

उग्राम् (ugrām) - fierce, formidable, terrible

(adjective)

Accusative, feminine, singular of ugra

ugra - fierce, terrible, formidable, mighty, violent, wrathful

दुस्तराम् (dustarām) - difficult to cross, hard to overcome

(adjective)

Accusative, feminine, singular of dustara

dustara - difficult to cross, hard to traverse, difficult to overcome

gerundive/future passive participle (indirectly)

From dus- (difficult) + tara (crossing, from root tṛ 'to cross')

Compound type : bahuvrīhi (dus+tara)

• dus – bad, ill, difficult
  indeclinable
  Prefix indicating difficulty or badness.
• tara – crossing, traversing, that which crosses
  noun
  from root tṛ (to cross)
  Suffix -a from root tṛ
  Root: tṛ (class 1)

अकृतात्मभिः (akṛtātmabhiḥ) - by those whose souls are not prepared, by the unprepared, by those lacking self-discipline

(adjective)

Instrumental, plural of akṛtātman

akṛtātman - one whose self (ātman) is not perfected, untrained, unprepared, lacking self-discipline, unholy

Negative compound 'a' + 'kṛtātman'

Compound type : bahuvrīhi (a+kṛta+ātman)

• a – not, non-, un-
  indeclinable
  Negative prefix
• kṛta – done, made, performed, prepared, perfected
  past passive participle
  Past Passive Participle
  From root kṛ (to do, make)
  Root: kṛ (class 8)
• ātman – self, soul, spirit, individual essence (ātman)
  noun (masculine)