महाभारतः mahābhārataḥ - book-7, chapter-65, verse-15

मन्दवेगतरा नागा बभूवुस्ते विचेतसः ।
शरैराशीविषस्पर्शैर्निर्भिन्नाः सव्यसाचिना ॥१५॥

15. mandavegatarā nāgā babhūvuste vicetasaḥ ,
śarairāśīviṣasparśairnirbhinnāḥ savyasācinā.

15. mandavegatarāḥ nāgāḥ babhūvuḥ te vicetasaḥ
śaraiḥ āśīviṣasparśaiḥ nirbhinnāḥ savyasācinā

15. te nāgāḥ savyasācinā āśīviṣasparśaiḥ śaraiḥ
nirbhinnāḥ mandavegatarāḥ vicetasaḥ babhūvuḥ

15. Those elephants, pierced by Arjuna (savya-sācin)'s arrows that felt like the touch of venomous snakes, became much slower and bewildered.

Words meanings summery:

• मन्दवेगतराः (mandavegatarāḥ) - much slower (slower in speed; having slower movement)

• नागाः (nāgāḥ) - elephants (elephants; serpents)

• बभूवुः (babhūvuḥ) - they became

• ते (te) - those

• विचेतसः (vicetasaḥ) - bewildered, senseless, distraught

• शरैः (śaraiḥ) - by arrows

• आशीविषस्पर्शैः (āśīviṣasparśaiḥ) - whose touch was like that of venomous snakes (by those having the touch of venomous snakes)

• निर्भिन्नाः (nirbhinnāḥ) - pierced, torn apart

• सव्यसाचिना (savyasācinā) - by Arjuna (savyasācin) (by the ambidextrous one)

Words meanings and morphology

मन्दवेगतराः (mandavegatarāḥ) - much slower (slower in speed; having slower movement)

(adjective)

Nominative, masculine, plural of mandavegatara

mandavegatara - slower in speed, having slower movement

comparative form of mandavega

Compound type : tatpuruṣa (manda+vega+tara)

• manda – slow, dull, gentle
  adjective (masculine)
• vega – speed, velocity, force
  noun (masculine)
  Root: vij (class 3)
• tara – more, exceedingly (comparative suffix)
  suffix
  comparative suffix

नागाः (nāgāḥ) - elephants (elephants; serpents)

(noun)

Nominative, masculine, plural of nāga

nāga - serpent, elephant

बभूवुः (babhūvuḥ) - they became

(verb)

3rd person , plural, active, perfect (lit) of bhū

Perfect

3rd person plural Perfect Active

Root: bhū (class 1)

ते (te) - those

(pronoun)

Nominative, masculine, plural of tad

tad - that, he, she, it

विचेतसः (vicetasaḥ) - bewildered, senseless, distraught

(adjective)

Nominative, masculine, plural of vicetas

vicetas - bewildered, senseless, distraught, unconscious

Compound type : bahuvrīhi (vi+cetas)

• vi – apart, away, without
  indeclinable
• cetas – mind, consciousness, understanding
  noun (neuter)
  Root: cit (class 1)

शरैः (śaraiḥ) - by arrows

(noun)

Instrumental, masculine, plural of śara

śara - arrow, reed

आशीविषस्पर्शैः (āśīviṣasparśaiḥ) - whose touch was like that of venomous snakes (by those having the touch of venomous snakes)

(adjective)

Instrumental, masculine, plural of āśīviṣasparśa

āśīviṣasparśa - having the touch of a venomous snake

Compound type : tatpuruṣa (āśīviṣa+sparśa)

• āśīviṣa – venomous snake
  noun (masculine)
• sparśa – touch, contact
  noun (masculine)
  Root: spṛś (class 6)

निर्भिन्नाः (nirbhinnāḥ) - pierced, torn apart

(adjective)

Nominative, masculine, plural of nirbhinna

nirbhinna - pierced, torn apart, broken through

Past Passive Participle

From √bhid (to cleave, split) with prefix nir-

Prefix: nir

Root: bhid (class 7)

सव्यसाचिना (savyasācinā) - by Arjuna (savyasācin) (by the ambidextrous one)

(proper noun)

Instrumental, masculine, singular of savyasācin

savyasācin - ambidextrous; epithet of Arjuna

Compound type : bahuvrīhi (savya+sācin)

• savya – left (hand)
  adjective (masculine)
• sācin – who draws (a bow)
  noun (masculine)
  From √sac (to accompany, follow) or possibly √sañj (to attach, cling to) with nominalizing suffix -in.