योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-113, verse-38

गुहागुलुगुलावर्तनिर्घोषाशनिभाषणान् ।
भृशं भावयतो ग्रस्तानगस्त्यौर्वानलानिव ॥ ३८ ॥

guhāgulugulāvartanirghoṣāśanibhāṣaṇān ,
bhṛśaṃ bhāvayato grastānagastyaurvānalāniva 38

38. guhāgulugulāvartanirghoṣāśanibhāṣaṇān bhṛśam
bhāvayataḥ grastān agastyāurvānalān iva

38. (saḥ) bhṛśam guhāgulugulāvartanirghoṣāśanibhāṣaṇān
agastyāurvānalān iva grastān bhāvayataḥ

38. He intensely perceives those who are swallowed, making roaring sounds like thunderbolts combined with the gurgling of whirlpools from caves, and appearing like the fires of Agastya and Aurva.

Words meanings summery:

• गुहागुलुगुलावर्तनिर्घोषाशनिभाषणान् (guhāgulugulāvartanirghoṣāśanibhāṣaṇān) - roaring with gurgling whirlpools in caves and sounds like thunderbolts (describing the swallowed ones) (making sounds like thunderbolts, loud gurgling whirlpools, and cave echoes)

• भृशम् (bhṛśam) - intensely (greatly, exceedingly, intensely)

• भावयतः (bhāvayataḥ) - of him who perceives (of one who causes to be, of one who perceives, of one who considers)

• ग्रस्तान् (grastān) - those who are swallowed/devoured (swallowed, devoured, seized)

• अगस्त्याउर्वानलान् (agastyāurvānalān) - like the destructive fires associated with Agastya and Aurva (like the fires of Agastya and Aurva)

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

Words meanings and morphology

गुहागुलुगुलावर्तनिर्घोषाशनिभाषणान् (guhāgulugulāvartanirghoṣāśanibhāṣaṇān) - roaring with gurgling whirlpools in caves and sounds like thunderbolts (describing the swallowed ones) (making sounds like thunderbolts, loud gurgling whirlpools, and cave echoes)

(adjective)

Accusative, masculine, plural of guhāgulugulāvartanirghoṣāśanibhāṣaṇa

guhāgulugulāvartanirghoṣāśanibhāṣaṇa - making roaring sounds like thunderbolts, loud gurgling whirlpools, and cave echoes

Compound type : tatpuruṣa (guhā+gulugulu+āvarta+nirghoṣa+aśani+bhāṣaṇa)

• guhā – cave, cavern
  noun (feminine)
  Root: guh (class 1)
• gulugulu – gurgling sound, rumbling sound (onomatopoeia)
  indeclinable
• āvarta – whirlpool, eddy, convolution, revolving
  noun (masculine)
  Prefix: ā
  Root: vṛt (class 1)
• nirghoṣa – loud sound, roar, noise
  noun (masculine)
  Prefix: nir
  Root: ghuṣ (class 1)
• aśani – thunderbolt, lightning, destructive weapon
  noun (masculine)
  Root: aś (class 5)
• bhāṣaṇa – speaking, talking, roaring, sound
  noun (neuter)
  Root: bhāṣ (class 1)

Note: Modifies 'grastān'.

भृशम् (bhṛśam) - intensely (greatly, exceedingly, intensely)

(indeclinable)

Note: Adverb modifying 'bhāvayataḥ'.

भावयतः (bhāvayataḥ) - of him who perceives (of one who causes to be, of one who perceives, of one who considers)

(participle)

Genitive, masculine, singular of bhāvayat

bhāvayat - causing to be, manifesting, perceiving, imagining

Present Active Participle

From causative root bhū (to be) + śatṛ suffix.

Root: bhū (class 1)

Note: Implied subject is the perceiver.

ग्रस्तान् (grastān) - those who are swallowed/devoured (swallowed, devoured, seized)

(participle)

Accusative, masculine, plural of grasta

grasta - swallowed, devoured, seized, eclipsed

Past Passive Participle

From root gras (to devour, swallow) + kta suffix.

Root: gras (class 1)

Note: Object of perception for 'bhāvayataḥ'.

अगस्त्याउर्वानलान् (agastyāurvānalān) - like the destructive fires associated with Agastya and Aurva (like the fires of Agastya and Aurva)

(noun)

Accusative, masculine, plural of agastyāurvānala

agastyāurvānala - the fires of Agastya and Aurva (destructive cosmic fires)

Compound type : dvandva (agastya+aurva+anala)

• agastya – Name of a great sage
  proper noun (masculine)
• aurva – related to Urva, a sage; name of a submarine fire
  noun (masculine)
  Derived from Urva.
• anala – fire, god of fire
  noun (masculine)
  Root: an (class 2)

Note: Refers to the fires themselves, implying destructive power.

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

(indeclinable)