योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-80, verse-4

तत एकार्णवापूरो विरिञ्चनगरान्तरम् ।
रात्रौ भुवमिव ध्वान्तं पूरयामास सूर्मिमान् ॥ ४ ॥

tata ekārṇavāpūro viriñcanagarāntaram ,
rātrau bhuvamiva dhvāntaṃ pūrayāmāsa sūrmimān 4

4. tataḥ eka-arṇava-āpūraḥ virañca-nagara-antaram
rātrau bhuvam iva dhvāntam pūrayāmāsa su-ūrmi-mān

4. tataḥ,
su-ūrmi-mān eka-arṇava-āpūraḥ,
rātrau dhvāntam bhuvam iva,
virañca-nagara-antaram pūrayāmāsa.

4. Then, a surging flood from the primal ocean (ekārṇava) filled the interior of Brahmā's city, just as darkness fills the earth at night.

Words meanings summery:

• ततः (tataḥ) - then, thereafter, from that

• एक-अर्णव-आपूरः (eka-arṇava-āpūraḥ) - a flood of the primal ocean

• विरञ्च-नगर-अन्तरम् (virañca-nagara-antaram) - the interior of Brahmā's city

• रात्रौ (rātrau) - at night

• भुवम् (bhuvam) - the earth, world

• इव (iva) - like, as if, similar to

• ध्वान्तम् (dhvāntam) - darkness

• पूरयामास (pūrayāmāsa) - he filled, it filled

• सु-ऊर्मि-मान् (su-ūrmi-mān) - having good waves, surging

Words meanings and morphology

ततः (tataḥ) - then, thereafter, from that

(indeclinable)

एक-अर्णव-आपूरः (eka-arṇava-āpūraḥ) - a flood of the primal ocean

(noun)

Nominative, masculine, singular of ekārṇavāpūra

ekārṇavāpūra - a flood or overflow of the single ocean (primal ocean)

Compound type : tatpuruṣa (eka+arṇava+āpūra)

• eka – one, single, sole
  adjective (masculine)
• arṇava – ocean, sea
  noun (masculine)
• āpūra – flood, overflow, fullness
  noun (masculine)
  From prefix 'ā' + root 'pṛ' (to fill).
  Prefix: ā
  Root: pṛ (class 3)

विरञ्च-नगर-अन्तरम् (virañca-nagara-antaram) - the interior of Brahmā's city

(noun)

Accusative, neuter, singular of virañcanagarāntara

virañcanagarāntara - the interior or inner part of Brahmā's city

Compound type : tatpuruṣa (virañci+nagara+antara)

• virañci – Viriñca, a name for Brahmā
  proper noun (masculine)
• nagara – city, town
  noun (neuter)
• antara – interior, inside, interval, space
  noun (neuter)

रात्रौ (rātrau) - at night

(noun)

Locative, feminine, singular of rātri

rātri - night

भुवम् (bhuvam) - the earth, world

(noun)

Accusative, feminine, singular of bhū

bhū - earth, ground, place, world

इव (iva) - like, as if, similar to

(indeclinable)

ध्वान्तम् (dhvāntam) - darkness

(noun)

Accusative, neuter, singular of dhvānta

dhvānta - darkness, gloom

From root 'dhvan' (to sound, to darken).

Root: dhvan (class 1)

पूरयामास (pūrayāmāsa) - he filled, it filled

(verb)

3rd person , singular, active, perfect (lit) of pūr

causative, perfect

Causative stem 'pūrayati' from root 'pṛ' (to fill), perfect form.

Root: pṛ (class 3)

सु-ऊर्मि-मान् (su-ūrmi-mān) - having good waves, surging

(adjective)

Nominative, masculine, singular of sūrmimat

sūrmimat - having good waves, well-waved, surging

Compound of 'su' (good), 'ūrmi' (wave), and suffix '-mat' (possessive).

Compound type : bahuvrīhi (su+ūrmi+mat)

• su – good, well, excellent
  prefix
• ūrmi – wave, billow, current
  noun (masculine)
• mat – possessing, having, endowed with
  suffix (masculine)
  Possessive suffix forming adjectives.

Note: Agrees with 'ekārṇavāpūraḥ'.