महाभारतः mahābhārataḥ - book-7, chapter-29, verse-9

स्यालौ तव महात्मानौ राजानौ वृषकाचलौ ।
भृशं निजघ्नतुः पार्थमिन्द्रं वृत्रबलाविव ॥९॥

9. syālau tava mahātmānau rājānau vṛṣakācalau ,
bhṛśaṁ nijaghnatuḥ pārthamindraṁ vṛtrabalāviva.

9. syālau tava mahātmānau rājānau vṛṣakācalau
bhṛśam nijaghṇatuḥ pārtham indram vṛtrabalau iva

9. tava syālau mahātmānau rājānau vṛṣakācalau
pārtham bhṛśam nijaghṇatuḥ indram vṛtrabalau iva

9. Your two great-souled brothers-in-law, the kings Vṛṣakācala, violently struck Arjuna, just as Vṛtra and Bala once struck Indra.

Words meanings summery:

• स्यालौ (syālau) - Refers to Vṛṣaka and Acala. (brothers-in-law)

• तव (tava) - Referring to the speaker's (Dhṛtarāṣṭra's) brothers-in-law. (your)

• महात्मानौ (mahātmānau) - Refers to Vṛṣaka and Acala, emphasizing their stature. (great-souled, noble-minded)

• राजानौ (rājānau) - Refers to Vṛṣaka and Acala as rulers. (kings)

• वृषकाचलौ (vṛṣakācalau) - Refers to the two brothers, Vṛṣaka and Acala. (Vṛṣakācala (name of two individuals))

• भृशम् (bhṛśam) - Describes the intensity of the striking. (greatly, intensely, violently)

• निजघ्णतुः (nijaghṇatuḥ) - The two brothers Vṛṣaka and Acala struck Arjuna. (they struck down, they killed)

• पार्थम् (pārtham) - Refers to Arjuna. (Arjuna (son of Pṛthā/Kuntī))

• इन्द्रम् (indram) - The Vedic deity Indra, here as the object of a simile. (Indra)

• वृत्रबलौ (vṛtrabalau) - The two demons who fought Indra. (Vṛtra and Bala (names of demons))

• इव (iva) - Introduces a simile. (as if, like, similar to)

Words meanings and morphology

स्यालौ (syālau) - Refers to Vṛṣaka and Acala. (brothers-in-law)

(noun)

Nominative, masculine, dual of syāla

syāla - wife's brother, brother-in-law

तव (tava) - Referring to the speaker's (Dhṛtarāṣṭra's) brothers-in-law. (your)

(pronoun)

Genitive, singular of yuṣmad

yuṣmad - you (pronoun)

Genitive singular form.

महात्मानौ (mahātmānau) - Refers to Vṛṣaka and Acala, emphasizing their stature. (great-souled, noble-minded)

(adjective)

Nominative, masculine, dual of mahātman

mahātman - great-souled, magnanimous, noble-minded

Compound type : bahuvrīhi (mahat+ātman)

• mahat – great, large
  adjective
• ātman – self, soul, spirit, essence
  noun (masculine)

राजानौ (rājānau) - Refers to Vṛṣaka and Acala as rulers. (kings)

(noun)

Nominative, masculine, dual of rājan

rājan - king, ruler

वृषकाचलौ (vṛṣakācalau) - Refers to the two brothers, Vṛṣaka and Acala. (Vṛṣakācala (name of two individuals))

(proper noun)

Nominative, masculine, dual of vṛṣakācala

vṛṣakācala - Vṛṣakācala (proper name, likely a dvandva compound of Vṛṣaka and Acala)

Compound type : dvandva (vṛṣaka+acala)

• vṛṣaka – Vṛṣaka (name)
  proper noun (masculine)
• acala – Acala (name)
  proper noun (masculine)

भृशम् (bhṛśam) - Describes the intensity of the striking. (greatly, intensely, violently)

(indeclinable)

Accusative singular neuter form used adverbially.

निजघ्णतुः (nijaghṇatuḥ) - The two brothers Vṛṣaka and Acala struck Arjuna. (they struck down, they killed)

(verb)

3rd person , dual, active, past perfect (lit) of han

Perfect tense, Parasmaipada, 3rd person dual

Reduplicated root 'han' (class 2) with prefix 'ni'.

Prefix: ni

Root: han (class 2)

पार्थम् (pārtham) - Refers to Arjuna. (Arjuna (son of Pṛthā/Kuntī))

(proper noun)

Accusative, masculine, singular of pārtha

pārtha - son of Pṛthā (Kuntī); Arjuna

इन्द्रम् (indram) - The Vedic deity Indra, here as the object of a simile. (Indra)

(proper noun)

Accusative, masculine, singular of indra

indra - Indra (king of the gods)

वृत्रबलौ (vṛtrabalau) - The two demons who fought Indra. (Vṛtra and Bala (names of demons))

(proper noun)

Nominative, masculine, dual of vṛtrabalau

vṛtrabalau - Vṛtra and Bala (names of two asuras/demons)

Dual form of a dvandva compound.

Compound type : dvandva (vṛtra+bala)

• vṛtra – Vṛtra (name of a demon)
  proper noun (masculine)
• bala – Bala (name of a demon)
  proper noun (masculine)

इव (iva) - Introduces a simile. (as if, like, similar to)

(indeclinable)

Particle of comparison.