योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-39, verse-2

रणरक्तरुचिर्व्योमदर्पणप्रतिबिम्बिता ।
जहौ सूर्यशिरश्छेदे संध्यालेखोदभूत्क्षणम् ॥ २ ॥

raṇaraktarucirvyomadarpaṇapratibimbitā ,
jahau sūryaśiraśchede saṃdhyālekhodabhūtkṣaṇam 2

2. raṇa-rakta-ruciḥ vyoma-darpaṇa-pratibimbitā jahau
sūrya-śiras-chede sandhyā-lekhaḥ udabhūt kṣaṇam

2. raṇa-rakta-ruciḥ vyoma-darpaṇa-pratibimbitā (sūryasya) sūrya-śiras-chede (sūryam) jahau (tataḥ) kṣaṇam sandhyā-lekhaḥ udabhūt.

2. The radiance (ruciḥ) that was red like battle-blood, reflected in the mirror of the sky, departed at the severing of the sun's head (i.e., its setting). Instantly, a streak of twilight (sandhyā) appeared.

Words meanings summery:

• रण-रक्त-रुचिः (raṇa-rakta-ruciḥ) - radiance, red with the hue of battle/blood (splendor/color red like battle)

• व्योम-दर्पण-प्रतिबिम्बिता (vyoma-darpaṇa-pratibimbitā) - reflected in the mirror-like sky (reflected in the mirror of the sky)

• जहौ (jahau) - departed, vanished (referring to the previous state of light) (abandoned, left, gave up, cast off)

• सूर्य-शिरस्-छेदे (sūrya-śiras-chede) - at the time of the sun's setting (metaphorically, its head being cut off) (at the cutting of the sun's head)

• सन्ध्या-लेखः (sandhyā-lekhaḥ) - a line of twilight (streak/line of twilight)

• उदभूत् (udabhūt) - appeared, arose (arose, appeared, sprang up)

• क्षणम् (kṣaṇam) - instantly (a moment, instantly, in a moment)

Words meanings and morphology

रण-रक्त-रुचिः (raṇa-rakta-ruciḥ) - radiance, red with the hue of battle/blood (splendor/color red like battle)

(noun)

Nominative, feminine, singular of raṇa-rakta-ruci

raṇa-rakta-ruci - color/splendor like battle-blood

Tatpuruṣa compound.

Compound type : Tatpuruṣa (raṇa+rakta+ruci)

• raṇa – battle, war
  noun (masculine)
  Root: raṇ (class 1)
• rakta – red, colored, dyed
  adjective
  Past Passive Participle
  From root rañj (to color).
  Root: rañj (class 1)
• ruci – light, splendor, color, beauty, delight
  noun (feminine)
  From root ruc (to shine).
  Root: ruc (class 1)

Note: Refers to the red glow of twilight.

व्योम-दर्पण-प्रतिबिम्बिता (vyoma-darpaṇa-pratibimbitā) - reflected in the mirror-like sky (reflected in the mirror of the sky)

(adjective)

Nominative, feminine, singular of vyoma-darpaṇa-pratibimbita

vyoma-darpaṇa-pratibimbita - reflected in the sky-mirror

Tatpuruṣa compound ending with a Past Passive Participle.

Compound type : Tatpuruṣa (vyoma+darpaṇa+pratibimbita)

• vyoma – sky, atmosphere
  noun (neuter)
• darpaṇa – mirror
  noun (masculine)
  From root dṛp (to swell, to be proud).
  Root: dṛp (class 4)
• pratibimbita – reflected, mirrored
  adjective
  Past Passive Participle
  From root bimb (to reflect) with prefix prati.
  Prefix: prati
  Root: bimb (class 1)

जहौ (jahau) - departed, vanished (referring to the previous state of light) (abandoned, left, gave up, cast off)

(verb)

3rd person , singular, active, past perfect (lit) of hā

Perfect tense, third person singular active.

Perfect form of root hā (to abandon), with reduplication and vṛddhi.

Root: hā (class 3)

सूर्य-शिरस्-छेदे (sūrya-śiras-chede) - at the time of the sun's setting (metaphorically, its head being cut off) (at the cutting of the sun's head)

(noun)

Locative, masculine, singular of sūrya-śiras-cheda

sūrya-śiras-cheda - cutting of the sun's head

Tatpuruṣa compound.

Compound type : Tatpuruṣa (sūrya+śiras+cheda)

• sūrya – sun
  noun (masculine)
• śiras – head
  noun (neuter)
• cheda – cutting, severing
  noun (masculine)
  From root chid (to cut).
  Root: chid (class 7)

सन्ध्या-लेखः (sandhyā-lekhaḥ) - a line of twilight (streak/line of twilight)

(noun)

Nominative, masculine, singular of sandhyā-lekha

sandhyā-lekha - streak of twilight

Tatpuruṣa compound.

Compound type : Tatpuruṣa (sandhyā+lekha)

• sandhyā – twilight, evening, junction
  noun (feminine)
  From sam-dhi (joining).
  Prefix: sam
  Root: dhā (class 3)
• lekha – line, streak, writing
  noun (masculine)
  From root likh (to scratch, write).
  Root: likh (class 6)

उदभूत् (udabhūt) - appeared, arose (arose, appeared, sprang up)

(verb)

3rd person , singular, active, past imperfect (laṅ) of ud-bhū

Imperfect tense, third person singular active.

Augment 'a-' + prefix 'ud-' + root 'bhū' (converted to 'bhav') + imperfect ending 't'.

Prefix: ud

Root: bhū (class 1)

क्षणम् (kṣaṇam) - instantly (a moment, instantly, in a moment)

(indeclinable)

Used adverbially in accusative singular.

Root: kṣaṇ (class 1)

Note: Adverbial use of accusative singular.