योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-54, verse-63

अथैतस्मिन्महालोके तिष्ठन्नुद्दालकश्चिरम् ।
अपश्यद्व्योमगान्सिद्धानमरानपि भूरिशः ॥ ६३ ॥

athaitasminmahāloke tiṣṭhannuddālakaściram ,
apaśyadvyomagānsiddhānamarānapi bhūriśaḥ 63

63. atha etasmin mahāloke tiṣṭhan uddālakaḥ ciram
apaśyat vyomagān siddhān amarān api bhūriśaḥ

63. atha uddālakaḥ etasmin mahāloke ciram tiṣṭhan
bhūriśaḥ vyomagān siddhān api amarān apaśyat

63. Then, Uddālaka, remaining in this great realm for a long time, saw many sky-traveling accomplished beings (Siddhas) and also immortals.

Words meanings summery:

• अथ (atha) - then, subsequently (then; now; therefore; thereupon)

• एतस्मिन् (etasmin) - in this (great realm) (in this; upon this)

• महालोके (mahāloke) - in this higher, spiritual realm (in the great world; in the great realm)

• तिष्ठन् (tiṣṭhan) - while remaining, abiding (remaining; standing; abiding)

• उद्दालकः (uddālakaḥ) - the sage Uddālaka (Uddālaka (a sage's name))

• चिरम् (ciram) - for a long duration (for a long time; long; ancient)

• अपश्यत् (apaśyat) - he perceived/saw (with spiritual vision) (he saw; he perceived)

• व्योमगान् (vyomagān) - beings who travel through the air/space (sky-goers; those who move in the sky)

• सिद्धान् (siddhān) - celestial beings, perfected beings (Siddhas) (perfected ones; accomplished ones; successful ones)

• अमरान् (amarān) - celestial gods (immortals; gods)

• अपि (api) - and also (also; even; too)

• भूरिशः (bhūriśaḥ) - in great numbers; many (abundantly; greatly; many; much)

Words meanings and morphology

अथ (atha) - then, subsequently (then; now; therefore; thereupon)

(indeclinable)

Note: Used to introduce a new topic or sequence.

एतस्मिन् (etasmin) - in this (great realm) (in this; upon this)

(pronoun)

Locative, neuter, singular of etad

etad - this; here

Note: Refers to the 'mahāloka'.

महालोके (mahāloke) - in this higher, spiritual realm (in the great world; in the great realm)

(noun)

Locative, masculine, singular of mahāloka

mahāloka - great world; higher realm; a celestial plane

Compound type : karmadhāraya (mahā+loka)

• mahā – great; mighty; large
  adjective (feminine)
• loka – world; realm; people; vision
  noun (masculine)
  From √lok 'to see'.
  Root: lok (class 1)

तिष्ठन् (tiṣṭhan) - while remaining, abiding (remaining; standing; abiding)

(participle)

Nominative, masculine, singular of sthā

sthā - to stand; to remain; to abide; to stay

Root: sthā (class 1)

Note: Present active participle, modifying Uddālaka.

उद्दालकः (uddālakaḥ) - the sage Uddālaka (Uddālaka (a sage's name))

(proper noun)

Nominative, masculine, singular of uddālaka

uddālaka - name of a sage, also a plant

Note: Subject of the sentence.

चिरम् (ciram) - for a long duration (for a long time; long; ancient)

(indeclinable)

Note: Adverb of time.

अपश्यत् (apaśyat) - he perceived/saw (with spiritual vision) (he saw; he perceived)

(verb)

3rd person , singular, active, imperfect past (laṅ) of dṛś

Root: dṛś (class 1)

Note: The initial 'a' is the augment for the imperfect tense.

व्योमगान् (vyomagān) - beings who travel through the air/space (sky-goers; those who move in the sky)

(noun)

Accusative, masculine, plural of vyomaga

vyomaga - sky-goer; moving in the air; bird; cloud

Compound of vyoman ('sky') and ga ('goer' from √gam).

Compound type : upapada-tatpuruṣa (vyoman+ga)

• vyoman – sky; atmosphere; space
  noun (neuter)
• ga – going; moving; mover; situated in
  adjective (masculine)
  Agent noun/suffix
  Derived from root √gam 'to go'.
  Root: gam (class 1)

Note: Object of 'apaśyat'.

सिद्धान् (siddhān) - celestial beings, perfected beings (Siddhas) (perfected ones; accomplished ones; successful ones)

(noun)

Accusative, masculine, plural of siddha

siddha - perfected; accomplished; successful; a class of semi-divine beings (Siddhas)

Past Passive Participle

Derived from root √sidh 'to accomplish, succeed'.

Root: sidh (class 4)

Note: Object of 'apaśyat'.

अमरान् (amarān) - celestial gods (immortals; gods)

(noun)

Accusative, masculine, plural of amara

amara - immortal; god; deity

Negation of mara ('mortal') by prefix 'a-'.

Note: Object of 'apaśyat'.

अपि (api) - and also (also; even; too)

(indeclinable)

Note: Connects 'Siddhas' and 'immortals'.

भूरिशः (bhūriśaḥ) - in great numbers; many (abundantly; greatly; many; much)

(indeclinable)

Derived from bhūri ('ample, abundant') with suffix -śaḥ.

Note: Modifies the seen beings, indicating their multitude.