योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-36, verse-6

अश्वौघो मिलदश्वानां वृन्देनाराविरंहसा ।
तरङ्गौघेन घोषेण तरङ्गौघ इवार्णवे ॥ ६ ॥

aśvaugho miladaśvānāṃ vṛndenārāviraṃhasā ,
taraṅgaughena ghoṣeṇa taraṅgaugha ivārṇave 6

6. aśvaughaḥ miladaśvānām vṛndena arāvirahaṃsā
taraṅgaughena ghoṣeṇa taraṅgaugha iva arṇave

6. aśvaughaḥ miladaśvānām vṛndena arāvirahaṃsā
taraṅgaughena ghoṣeṇa arṇave taraṅgaugha iva

6. A multitude of horses, engaging with a host of rapidly advancing horses with unimpeded speed, created a roar like that produced by a multitude of waves, similar to a great many waves in the ocean itself.

Words meanings summery:

• अश्वौघः (aśvaughaḥ) - multitude of horses, flood of horses, cavalry host

• मिलदश्वानाम् (miladaśvānām) - of the horses of the opposing army that are mingling in battle (of mingling horses, of rushing horses, of clashing horses)

• वृन्देन (vṛndena) - by the host of opposing horses (by the host, by the multitude, by the herd)

• अराविरहंसा (arāvirahaṁsā) - characterizing the rapid advance of the horse host (with unimpeded speed, with unobstructed speed)

• तरङ्गौघेन (taraṅgaughena) - by the multitude of waves, by the flood of waves

• घोषेण (ghoṣeṇa) - by the roar, by the sound, by the din

• तरङ्गौघ (taraṅgaugha) - a multitude of waves, a flood of waves

• इव (iva) - like, as, as if, similar to

• अर्णवे (arṇave) - in the ocean, in the sea

Words meanings and morphology

अश्वौघः (aśvaughaḥ) - multitude of horses, flood of horses, cavalry host

(noun)

Nominative, masculine, singular of aśvaugha

aśvaugha - multitude of horses, flood of horses, cavalry host

Compound type : tatpurusha (aśva+ogha)

• aśva – horse
  noun (masculine)
• ogha – flood, multitude, mass
  noun (masculine)

Note: Subject of an implied verb like 'fought' or 'sounded'.

मिलदश्वानाम् (miladaśvānām) - of the horses of the opposing army that are mingling in battle (of mingling horses, of rushing horses, of clashing horses)

(noun)

Genitive, masculine, plural of miladaśva

miladaśva - mingling horse, rushing horse, clashing horse

Present Active Participle (milat) + noun (aśva)

Compound of 'milat' (present active participle of root mil-, to join) and 'aśva' (horse).

Compound type : tatpurusha (milat+aśva)

• milat – mingling, joining, rushing, meeting
  adjective (masculine)
  Present Active Participle
  Derived from root 'mil' (to join, to meet).
  Root: mil (class 6)
• aśva – horse
  noun (masculine)

Note: Modifies 'vṛndena'.

वृन्देन (vṛndena) - by the host of opposing horses (by the host, by the multitude, by the herd)

(noun)

Instrumental, neuter, singular of vṛnda

vṛnda - host, multitude, herd, flock

Note: Indicates the agent or means of encounter.

अराविरहंसा (arāvirahaṁsā) - characterizing the rapid advance of the horse host (with unimpeded speed, with unobstructed speed)

(adjective)

Instrumental, neuter, singular of arāvirahaṃs

arāvirahaṁs - having unimpeded speed, whose speed is unhindered

Bahuvrihi compound 'a' (not) + 'rāvin' (obstructing) + 'raṃhas' (speed).

Compound type : bahuvrihi (a+rāvin+raṃhas)

• a – not, un-
  indeclinable
  Negative prefix.
• rāvin – obstructing, hindering, noisy
  adjective (masculine)
  Agent noun from root 'rā' (to give, bestow, or make noise). In context of 'a-' and 'raṃhas', it implies 'obstructing'.
  Root: rā (class 2)
• raṃhas – speed, impetus, force
  noun (neuter)
  From root 'ramh' (to go swiftly).
  Root: ramh (class 1)

Note: Agrees with 'vṛndena'.

तरङ्गौघेन (taraṅgaughena) - by the multitude of waves, by the flood of waves

(noun)

Instrumental, masculine, singular of taraṅgaugha

taraṅgaugha - multitude of waves, flood of waves

Compound type : tatpurusha (taraṅga+ogha)

• taraṅga – wave
  noun (masculine)
  From root 'tṛ' (to cross, go over) with suffix 'aṅga'.
  Root: tṛ (class 1)
• ogha – flood, multitude, mass
  noun (masculine)

Note: Used in a simile, indicating the source of a sound.

घोषेण (ghoṣeṇa) - by the roar, by the sound, by the din

(noun)

Instrumental, masculine, singular of ghoṣa

ghoṣa - roar, sound, noise, din

From root 'ghuṣ' (to sound).

Root: ghuṣ (class 1)

Note: Used in a simile, indicating the sound itself.

तरङ्गौघ (taraṅgaugha) - a multitude of waves, a flood of waves

(noun)

Nominative, masculine, singular of taraṅgaugha

taraṅgaugha - multitude of waves, flood of waves

Compound type : tatpurusha (taraṅga+ogha)

• taraṅga – wave
  noun (masculine)
  From root 'tṛ' (to cross, go over) with suffix 'aṅga'.
  Root: tṛ (class 1)
• ogha – flood, multitude, mass
  noun (masculine)

Note: Used as the subject in a simile.

इव (iva) - like, as, as if, similar to

(indeclinable)

Particle of comparison.

अर्णवे (arṇave) - in the ocean, in the sea

(noun)

Locative, masculine, singular of arṇava

arṇava - ocean, sea

Derived from 'arṇa' (water) + suffix 'va'.