योगवासिष्ठः yogavāsiṣṭhaḥ - book-1, chapter-20, verse-15

हार्दान्धकारकारिण्या भैरवाकारवानपि ।
यौवनाज्ञानयामिन्या बिभेति भगवानपि ॥ १५ ॥

hārdāndhakārakāriṇyā bhairavākāravānapi ,
yauvanājñānayāminyā bibheti bhagavānapi 15

15. hārda-andhakāra-kāriṇyā bhairava-ākāra-vān api
yauvana-ajñāna-yāminyā bibheti bhagavān api

15. bhagavān api bhairava-ākāra-vān api
hārda-andhakāra-kāriṇyā yauvana-ajñāna-yāminyā bibheti

15. Even the Lord (Bhagavān), though possessing a formidable appearance, fears the night of ignorance (ajñāna) which is youth (yauvana), because it causes darkness in the heart (hārda).

Words meanings summery:

• हार्द-अन्धकार-कारिण्या (hārda-andhakāra-kāriṇyā) - by that which causes darkness in the heart; causing inner darkness

• भैरव-आकार-वान् (bhairava-ākāra-vān) - possessing a terrible form; having a dreadful appearance

• अपि (api) - even; also; moreover

• यौवन-अज्ञान-यामिन्या (yauvana-ajñāna-yāminyā) - by the night of youth's ignorance; by the night of ignorance that is youth

• बिभेति (bibheti) - fears; is afraid of

• भगवान् (bhagavān) - a revered deity or sage (the Lord; the revered one; the divine one)

• अपि (api) - even; also; moreover

Words meanings and morphology

हार्द-अन्धकार-कारिण्या (hārda-andhakāra-kāriṇyā) - by that which causes darkness in the heart; causing inner darkness

(adjective)

Instrumental, feminine, singular of hārda-andhakāra-kāriṇī

hārda-andhakāra-kāriṇī - that which produces darkness in the heart/mind; cause of inner gloom

From hārda (relating to the heart) + andhakāra (darkness) + kāriṇī (female agent causing).

Compound type : tatpuruṣa (hārda+andhakāra+kāriṇī)

• hārda – relating to the heart; inner; heartfelt
  adjective (neuter)
  From hṛd (heart)
• andhakāra – darkness; gloom
  noun (masculine)
• kāriṇī – causing; making; performing (feminine agent)
  noun (feminine)
  Agent Noun
  Feminine of kārin, from √kṛ (to do, make)
  Root: kṛ (class 8)

Note: Modifies yauvana-ajñāna-yāminyā.

भैरव-आकार-वान् (bhairava-ākāra-vān) - possessing a terrible form; having a dreadful appearance

(adjective)

Nominative, masculine, singular of bhairava-ākāra-vat

bhairava-ākāra-vat - one having a terrifying form; dreadful-looking

From bhairava (terrible) + ākāra (form) + possessive suffix -vat.

Compound type : tatpuruṣa (bhairava+ākāra+vat)

• bhairava – terrible; dreadful; formidable
  adjective (masculine)
  Related to bhīru (fearful) or bhī (fear)
• ākāra – form; shape; appearance; aspect
  noun (masculine)
  From ā-√kṛ (to do, make)
  Prefix: ā
  Root: kṛ (class 8)
• vat – having; possessing; like (suffix)
  suffix (masculine)
  Possessive suffix

Note: Modifies bhagavān.

अपि (api) - even; also; moreover

(indeclinable)

Note: Emphatic particle after bhairava-ākāra-vān.

यौवन-अज्ञान-यामिन्या (yauvana-ajñāna-yāminyā) - by the night of youth's ignorance; by the night of ignorance that is youth

(noun)

Instrumental, feminine, singular of yauvana-ajñāna-yāminī

yauvana-ajñāna-yāminī - the night of ignorance which is youth; the dark night of youth's unawareness

From yauvana (youth) + ajñāna (ignorance) + yāminī (night). A karmadhāraya compound where youth is likened to the night of ignorance.

Compound type : karmadhāraya (yauvana+ajñāna+yāminī)

• yauvana – youth; youthfulness
  noun (neuter)
• ajñāna – ignorance; lack of knowledge
  noun (neuter)
  From a- + √jñā (to know)
  Prefix: a
  Root: jñā (class 9)
• yāminī – night
  noun (feminine)

Note: This is the object of fear, indicating 'by' or 'from' what he fears.

बिभेति (bibheti) - fears; is afraid of

(verb)

3rd person , singular, active, present indicative (laṭ) of bhī

Root: bhī (class 3)

Note: The subject is bhagavān.

भगवान् (bhagavān) - a revered deity or sage (the Lord; the revered one; the divine one)

(noun)

Nominative, masculine, singular of bhagavat

bhagavat - blessed; prosperous; divine; venerable; the Lord (Bhagavān)

Possessive adjective from bhaga (fortune) with suffix -vat.

Note: Subject of the verb bibheti.

अपि (api) - even; also; moreover

(indeclinable)

Note: Emphatic particle after bhagavān.