योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-126, verse-25

प्रधानदेवो भूत्वासौ लोकालोकगिरिं गतः ।
अस्य भूमण्डलतरोरालवालमिव स्थितम् ॥ २५ ॥

pradhānadevo bhūtvāsau lokālokagiriṃ gataḥ ,
asya bhūmaṇḍalatarorālavālamiva sthitam 25

25. pradhānadevaḥ bhūtvā asau lokālokagirim gataḥ
asya bhūmaṇḍalatoroḥ ālavālam iva sthitam

25. asau pradhānadevaḥ bhūtvā asya bhūmaṇḍalatoroḥ
ālavālam iva sthitam lokālokagirim gataḥ

25. Having become the chief deity, he went to the Lokāloka mountain, which was situated like the basin (for water) around the root of this tree of the terrestrial sphere.

Words meanings summery:

• प्रधानदेवः (pradhānadevaḥ) - chief deity (chief god, principal deity)

• भूत्वा (bhūtvā) - having become (having become, having been)

• असौ (asau) - he (that one, he/she/it)

• लोकालोकगिरिम् (lokālokagirim) - to the Lokāloka mountain

• गतः (gataḥ) - went (gone, went, reached)

• अस्य (asya) - of this (of this, his)

• भूमण्डलतोरोः (bhūmaṇḍalatoroḥ) - of the tree of the terrestrial sphere

• आलवालम् (ālavālam) - basin (for water) (basin for water around a tree's root)

• इव (iva) - like (like, as, as if)

• स्थितम् (sthitam) - situated (situated, stood, remained)

Words meanings and morphology

प्रधानदेवः (pradhānadevaḥ) - chief deity (chief god, principal deity)

(noun)

Nominative, masculine, singular of pradhānadeva

pradhānadeva - chief god, principal deity

Compound type : karmadhāraya (pradhāna+deva)

• pradhāna – chief, principal, main, most important
  adjective (neuter)
• deva – god, deity, celestial being
  noun (masculine)
  Root: div (class 4)

Note: Predicate nominative after 'bhūtvā'.

भूत्वा (bhūtvā) - having become (having become, having been)

(indeclinable)

absolutive

Derived from root 'bhū'.

Root: bhū (class 1)

Note: Indicates prior action to 'gataḥ'.

असौ (asau) - he (that one, he/she/it)

(pronoun)

Nominative, masculine, singular of adas

adas - that, this, he, she, it (demonstrative pronoun, often referring to something distant or previously mentioned)

Note: Subject of the sentence, referring to the same person from previous verses.

लोकालोकगिरिम् (lokālokagirim) - to the Lokāloka mountain

(proper noun)

Accusative, masculine, singular of lokālokagiri

lokālokagiri - the mythical Lokāloka mountain (separating the known world from the world of darkness)

Compound type : tatpuruṣa (lokāloka+giri)

• lokāloka – the mythical mountain separating the visible world from the region of darkness
  proper noun (masculine)
• giri – mountain, hill
  noun (masculine)

Note: Direct object of 'gataḥ'.

गतः (gataḥ) - went (gone, went, reached)

(adjective)

Nominative, masculine, singular of gata

gata - gone, went, reached, obtained

past passive participle

Derived from root 'gam'.

Root: gam (class 1)

Note: Predicate adjective, acts as the main verb.

अस्य (asya) - of this (of this, his)

(pronoun)

Genitive, neuter, singular of idam

idam - this (demonstrative pronoun)

Note: Refers to the 'bhūmaṇḍalatoru'.

भूमण्डलतोरोः (bhūmaṇḍalatoroḥ) - of the tree of the terrestrial sphere

(noun)

Genitive, masculine, singular of bhūmaṇḍalatoru

bhūmaṇḍalatoru - the tree representing the terrestrial sphere

Compound type : ṣaṣṭhī tatpuruṣa (bhūmaṇḍala+taru)

• bhūmaṇḍala – terrestrial sphere, the globe of the earth
  noun (neuter)
• taru – tree
  noun (masculine)

आलवालम् (ālavālam) - basin (for water) (basin for water around a tree's root)

(noun)

Nominative, neuter, singular of ālavāla

ālavāla - a basin of water around the root of a tree, a trench for watering plants

Note: Used in the simile to describe the mountain.

इव (iva) - like (like, as, as if)

(indeclinable)

Note: Introduces a simile.

स्थितम् (sthitam) - situated (situated, stood, remained)

(adjective)

Nominative, neuter, singular of sthita

sthita - stood, situated, existing, remained

past passive participle

Derived from root 'sthā'.

Root: sthā (class 1)

Note: Modifies 'ālavālam', describing its state. Or can be taken as an adverbial adjunct to 'gataḥ' (went, being situated).