योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-35, verse-12

गमागमपरानन्तपताकाच्छत्रफेनिलः ।
वहद्रक्तनदीरंहःप्रोह्यमानरथद्रुमः ॥ १२ ॥

gamāgamaparānantapatākācchatraphenilaḥ ,
vahadraktanadīraṃhaḥprohyamānarathadrumaḥ 12

12. gamāgamaparānantapatākācchatraphenilaḥ
vahadraktanadīraṃhaḥprohyamānarathadrumaḥ

12. gamāgamaparānantapatākācchatraphenilaḥ
vahadraktanadīraṃhaḥprohyamānarathadrumaḥ

12. It was frothy with countless flags and parasols moving to and fro, and it possessed chariots being swept away like trees by the swift current of a flowing river of blood.

Words meanings summery:

• गमागमपरानन्तपताकाच्छत्रफेनिलः (gamāgamaparānantapatākācchatraphenilaḥ) - frothy with countless flags and parasols moving to and fro

• वहद्रक्तनदीरंहःप्रोह्यमानरथद्रुमः (vahadraktanadīraṁhaḥprohyamānarathadrumaḥ) - having chariots like trees carried away by the current of a flowing river of blood

Words meanings and morphology

गमागमपरानन्तपताकाच्छत्रफेनिलः (gamāgamaparānantapatākācchatraphenilaḥ) - frothy with countless flags and parasols moving to and fro

(adjective)

Nominative, masculine, singular of gamāgamaparānantapatākācchatraphenila

gamāgamaparānantapatākācchatraphenila - possessing froth formed by flags and umbrellas that are endlessly coming and going

Compound type : bahuvrīhi (gamāgama+parānanta+patākā+chatra+phenila)

• gamāgama – coming and going, movement, circulation
  noun (masculine)
  Dvandva compound of gama (going) and āgama (coming).
  Root: √gam (class 1)
• parānanta – most endless, boundless, infinite
  adjective
  Compound of para (supreme, ultimate) and ananta (endless).
• patākā – banner, flag, standard
  noun (feminine)
• chatra – umbrella, parasol
  noun (neuter)
• phenila – foamy, frothy, covered with foam
  adjective
  Derived from phena (foam) with suffix -ila.

Note: Bahuvrīhi compound describing the battle as frothy due to these elements.

वहद्रक्तनदीरंहःप्रोह्यमानरथद्रुमः (vahadraktanadīraṁhaḥprohyamānarathadrumaḥ) - having chariots like trees carried away by the current of a flowing river of blood

(adjective)

Nominative, masculine, singular of vahadraktanadīraṃhaḥprohyamānarathadruma

vahadraktanadīraṁhaḥprohyamānarathadruma - possessing chariots compared to trees, being swept away by the current of a flowing river of blood

Compound type : bahuvrīhi (vahat+rakta+nadī+raṃhas+praūhyamāna+ratha+druma)

• vahat – flowing, carrying, bearing
  adjective
  Present Active Participle
  Derived from root √vah (to flow, carry).
  Root: √vah (class 1)
• rakta – blood, red
  noun (neuter)
• nadī – river
  noun (feminine)
• raṃhas – speed, velocity, current, force
  noun (neuter)
• praūhyamāna – being swept along, being carried away, being moved
  adjective
  Present Passive Participle
  Derived from root √ūh (to push, move) with prefix pra- and passive suffix -yamāna.
  Prefix: pra
  Root: √ūh (class 1)
• ratha – chariot
  noun (masculine)
• druma – tree
  noun (masculine)

Note: Bahuvrīhi compound describing the battle.