महाभारतः mahābhārataḥ - book-6, chapter-45, verse-51

अथ शल्यो गदापाणिरवतीर्य महारथात् ।
शङ्खस्य चतुरो वाहानहनद्भरतर्षभ ॥५१॥

51. atha śalyo gadāpāṇiravatīrya mahārathāt ,
śaṅkhasya caturo vāhānahanadbharatarṣabha.

51. atha śalyaḥ gadā-pāṇiḥ avatīrya mahā-rathāt
śaṅkhasya caturaḥ vāhān ahanat bharatarṣabha

51. atha bharatarṣabha śalyaḥ gadā-pāṇiḥ mahā-rathāt
avatīrya śaṅkhasya caturaḥ vāhān ahanat

51. Then, Shalya, holding a mace, descended from the great chariot and struck down Shankha's four horses, O best of the Bharatas.

Words meanings summery:

• अथ (atha) - now, then, thereupon

• शल्यः (śalyaḥ) - Shalya (name of a king)

• गदा-पाणिः (gadā-pāṇiḥ) - mace in hand, holding a mace

• अवतीर्य (avatīrya) - having descended

• महा-रथात् (mahā-rathāt) - from the great chariot, from the war-car

• शङ्खस्य (śaṅkhasya) - of Shankha

• चतुरः (caturaḥ) - four

• वाहान् (vāhān) - horses, steeds, bearers

• अहनत् (ahanat) - he struck, he killed

• भरतर्षभ (bharatarṣabha) - O best of the Bharatas

Words meanings and morphology

अथ (atha) - now, then, thereupon

(indeclinable)

शल्यः (śalyaḥ) - Shalya (name of a king)

(proper noun)

Nominative, masculine, singular of śalya

śalya - Shalya (a proper name, king of Madras)

गदा-पाणिः (gadā-pāṇiḥ) - mace in hand, holding a mace

(adjective)

Nominative, masculine, singular of gadā-pāṇi

gadā-pāṇi - one whose hand is a mace; one who has a mace in hand

Compound type : bahuvrihi (gadā+pāṇi)

• gadā – mace, club
  noun (feminine)
• pāṇi – hand
  noun (masculine)

Note: Adjective modifying "śalyaḥ".

अवतीर्य (avatīrya) - having descended

(indeclinable)

absolutive (gerund)

Derived from root tṛ (to cross, go over) with upasargas ava and i, and suffix lyap.

Prefix: ava

Root: tṛ (class 1)

Note: Gerund, indicating an action completed before the main verb.

महा-रथात् (mahā-rathāt) - from the great chariot, from the war-car

(noun)

Ablative, masculine, singular of mahā-ratha

mahā-ratha - great chariot, great warrior (riding a chariot)

Compound type : karmadhāraya (mahā+ratha)

• mahā – great, large
  adjective
• ratha – chariot, car
  noun (masculine)

शङ्खस्य (śaṅkhasya) - of Shankha

(proper noun)

Genitive, masculine, singular of śaṅkha

śaṅkha - conch shell, Shankha (a proper name)

Note: Possessive case for Shankha.

चतुरः (caturaḥ) - four

(numeral)

Note: Agrees with "vāhān".

वाहान् (vāhān) - horses, steeds, bearers

(noun)

Accusative, masculine, plural of vāha

vāha - bearing, carrying, a vehicle, horse, steed

Derived from root vah (to carry, bear)

Root: vah (class 1)

Note: Object of the verb "ahanat".

अहनत् (ahanat) - he struck, he killed

(verb)

3rd person , singular, active, imperfect (laṅ) of han

Root: han (class 2)

Note: The subject is Shalya.

भरतर्षभ (bharatarṣabha) - O best of the Bharatas

(noun)

Vocative, masculine, singular of bharata-ṛṣabha

bharata-ṛṣabha - bull among Bharatas, best of the Bharatas

Compound type : tatpurusha (bharata+ṛṣabha)

• bharata – a descendant of Bharata (name of a legendary king), a member of the Bharata clan
  proper noun (masculine)
• ṛṣabha – bull; chief, best, most excellent
  noun (masculine)

Note: An address, likely to Dhritarashtra or a general audience.