योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-54, verse-51

क्रमाच्छयामलतां यान्ति तस्य सर्वाक्षसंविदः ।
यथास्तं गच्छति रवौ मन्दालोकतया दिशं ॥ ५१ ॥

kramācchayāmalatāṃ yānti tasya sarvākṣasaṃvidaḥ ,
yathāstaṃ gacchati ravau mandālokatayā diśaṃ 51

51. kramāt śyāmalatām yānti tasya sarvākṣasaṃvidaḥ
yathā astam gacchati ravau manda-ālokatayā diśam

51. tasya sarvākṣasaṃvidaḥ kramāt śyāmalatām yānti
yathā ravau astam gacchati mandālokatayā diśam

51. Gradually, his perceptions of all senses attain a state of dullness, just as, when the sun sets, the direction (diśam) becomes dim due to the fading light.

Words meanings summery:

• क्रमात् (kramāt) - gradually, in due course, in succession, by degrees

• श्यामलताम् (śyāmalatām) - dullness, darkness, duskiness

• यान्ति (yānti) - go, attain, reach, proceed

• तस्य (tasya) - his, of him, of that

• सर्वाक्षसंविदः (sarvākṣasaṁvidaḥ) - perceptions of all senses

• यथा (yathā) - just as, as, like

• अस्तम् (astam) - in the context of the sun setting (setting, disappearance, going home)

• गच्छति (gacchati) - is setting (in reference to the sun) (goes, is going)

• रवौ (ravau) - when the sun (is setting) (in the sun, when the sun)

• मन्दालोकतया (mandālokatayā) - due to dim light, by means of dim light

• दिशम् (diśam) - the quarter of the sky, or visibility in that direction (direction, quarter)

Words meanings and morphology

क्रमात् (kramāt) - gradually, in due course, in succession, by degrees

(indeclinable)

Root: kram (class 1)

Note: Functions adverbially.

श्यामलताम् (śyāmalatām) - dullness, darkness, duskiness

(noun)

Accusative, feminine, singular of śyāmalatā

śyāmalatā - dullness, darkness, blackness, gloominess

Derived from śyāmala (dark, dusky) + -tā (suffix for abstract noun)

Note: Object of 'yānti'.

यान्ति (yānti) - go, attain, reach, proceed

(verb)

3rd person , plural, active, present (laṭ) of yā

Root: yā (class 2)

तस्य (tasya) - his, of him, of that

(pronoun)

Genitive, masculine, singular of tad

tad - that, he, she, it

Note: Modifies 'sarvākṣasaṃvidaḥ'.

सर्वाक्षसंविदः (sarvākṣasaṁvidaḥ) - perceptions of all senses

(noun)

Nominative, feminine, plural of sarvākṣasaṃvid

sarvākṣasaṁvid - perception or cognition of all senses

Compound: sarva (all) + akṣa (sense organ) + saṃvid (consciousness, perception)

Compound type : tatpurusha (sarva+akṣa+saṃvid)

• sarva – all, every, whole
  adjective (masculine)
• akṣa – sense organ (especially eye), axis, die
  noun (neuter)
• saṃvid – consciousness, knowledge, perception, understanding
  noun (feminine)
  Derived from sam-vid- 'to know together'
  Prefix: sam
  Root: vid (class 2)

Note: Subject of 'yānti'.

यथा (yathā) - just as, as, like

(indeclinable)

Note: Introduces the simile.

अस्तम् (astam) - in the context of the sun setting (setting, disappearance, going home)

(indeclinable)

Note: Forms part of the idiom 'astam gam' (to set).

गच्छति (gacchati) - is setting (in reference to the sun) (goes, is going)

(verb)

3rd person , singular, active, present (laṭ) of gam

Root: gam (class 1)

Note: Part of the locative absolute construction.

रवौ (ravau) - when the sun (is setting) (in the sun, when the sun)

(noun)

Locative, masculine, singular of ravi

ravi - sun, sun-god

Note: Forms locative absolute with 'gacchati'.

मन्दालोकतया (mandālokatayā) - due to dim light, by means of dim light

(noun)

Instrumental, feminine, singular of mandālokata

mandālokata - state of having dim light

Derived from manda-āloka (dim light) + -tā (suffix for abstract noun)

Compound type : tatpurusha (manda+āloka)

• manda – slow, dull, dim, faint
  adjective (masculine)
• āloka – light, sight, seeing
  noun (masculine)
  Derived from ā-lok- 'to perceive'
  Prefix: ā
  Root: lok (class 10)

Note: Expresses cause/reason.

दिशम् (diśam) - the quarter of the sky, or visibility in that direction (direction, quarter)

(noun)

Accusative, feminine, singular of diś

diś - direction, quarter of the sky, space

Root: diś (class 6)

Note: Object of an implied verb like 'becomes' or 'is affected'.