महाभारतः mahābhārataḥ - book-3, chapter-41, verse-18

ततस्त्वध्यापयामास सरहस्य निवर्तनम् ।
तदस्त्रं पाण्डवश्रेष्ठं मूर्तिमन्तमिवान्तकम् ॥१८॥

18. tatastvadhyāpayāmāsa sarahasya nivartanam ,
tadastraṁ pāṇḍavaśreṣṭhaṁ mūrtimantamivāntakam.

18. tataḥ tu adhyāpayāmāsa sarahasya nivartanam tat
astram pāṇḍavaśreṣṭham mūrtimantam iva antakam

18. Then, indeed, he taught the best of the Pāṇḍavas (Arjuna) that weapon, which included the secret of its retraction, as if it were Death (Antaka) embodied.

Words meanings summery:

• ततः (tataḥ) - thereupon, then, from that

• तु (tu) - but, indeed, however

• अध्यापयामास (adhyāpayāmāsa) - he taught

• सरहस्य (sarahasya) - with its secret, including the secret

• निवर्तनम् (nivartanam) - the method of retraction (of the weapon) (withdrawal, retraction, returning)

• तत् (tat) - that

• अस्त्रम् (astram) - weapon, missile

• पाण्डवश्रेष्ठम् (pāṇḍavaśreṣṭham) - to Arjuna, the best of the Pāṇḍavas (to the best of the Pāṇḍavas)

• मूर्तिमन्तम् (mūrtimantam) - embodied, having a form

• इव (iva) - like, as if

• अन्तकम् (antakam) - the deity Death (Antaka) (the Ender, Death)

Words meanings and morphology

ततः (tataḥ) - thereupon, then, from that

(indeclinable)

तु (tu) - but, indeed, however

(indeclinable)

अध्यापयामास (adhyāpayāmāsa) - he taught

(verb)

3rd person , singular, active, periphrastic perfect (liṭ) of adhyāpaya

causative

periphrastic perfect of causative stem from adhi + √i

Prefix: adhi

Root: i (class 2)

सरहस्य (sarahasya) - with its secret, including the secret

(adjective)

Accusative, neuter, singular of sarahasya

sarahasya - with (its) secret, mystical

Compound type : bahuvrihi (sa+rahasya)

• sa – with, together with
  indeclinable
• rahasya – secret, mystery
  noun (neuter)
  derived from rahas

Note: Modifies 'nivartanam'

निवर्तनम् (nivartanam) - the method of retraction (of the weapon) (withdrawal, retraction, returning)

(noun)

Accusative, neuter, singular of nivartana

nivartana - causing to turn back, withdrawal, retraction, returning

verbal noun

from ni + √vṛt (to turn, roll)

Prefix: ni

Root: vṛt (class 1)

तत् (tat) - that

(pronoun)

Accusative, neuter, singular of tad

tad - that, it

अस्त्रम् (astram) - weapon, missile

(noun)

Accusative, neuter, singular of astra

astra - missile, weapon

from √as (to throw, cast)

Root: as (class 4)

पाण्डवश्रेष्ठम् (pāṇḍavaśreṣṭham) - to Arjuna, the best of the Pāṇḍavas (to the best of the Pāṇḍavas)

(proper noun)

Accusative, masculine, singular of pāṇḍavaśreṣṭha

pāṇḍavaśreṣṭha - the best of the Pāṇḍavas

Compound type : tatpuruṣa (pāṇḍava+śreṣṭha)

• pāṇḍava – a descendant of Pāṇḍu
  proper noun (masculine)
• śreṣṭha – best, excellent, most excellent
  adjective (masculine)
  superlative of praśasya

मूर्तिमन्तम् (mūrtimantam) - embodied, having a form

(adjective)

Accusative, masculine, singular of mūrtimat

mūrtimat - having a body, embodied, personified

from mūrti + -mat (possessive suffix)

Note: Modifies 'antakam'

इव (iva) - like, as if

(indeclinable)

अन्तकम् (antakam) - the deity Death (Antaka) (the Ender, Death)

(noun)

Accusative, masculine, singular of antaka

antaka - ender, terminator, Death, Yama

from √ant (to end)

Root: ant (class 1)