महाभारतः mahābhārataḥ - book-5, chapter-155, verse-12

कृत्वा प्रतिज्ञां नाहत्वा निवर्तिष्यामि केशवम् ।
ततोऽन्वधावद्वार्ष्णेयं सर्वशस्त्रभृतां वरम् ॥१२॥

12. kṛtvā pratijñāṁ nāhatvā nivartiṣyāmi keśavam ,
tato'nvadhāvadvārṣṇeyaṁ sarvaśastrabhṛtāṁ varam.

12. kṛtvā pratijñām na ahatvā nivartiṣyāmi keśavam
tataḥ anvadhāvat vārṣṇeyam sarvaśastrabṛtām varam

12. pratijñām kṛtvā,
"keśavam ahatvā na nivartiṣyāmi",
tataḥ sarvaśastrabṛtām varam vārṣṇeyam anvadhāvat.

12. Having made the vow, "I shall not return without having killed Keśava (Krishna)," he then pursued the best among all weapon-wielders, the scion of Vṛṣṇi (Krishna).

Words meanings summery:

• कृत्वा (kṛtvā) - having done, having made, having performed

• प्रतिज्ञाम् (pratijñām) - vow, promise, oath

• न (na) - not, no

• अहत्वा (ahatvā) - without having killed

• निवर्तिष्यामि (nivartiṣyāmi) - I will return

• केशवम् (keśavam) - Krishna (Keśava)

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

• अन्वधावत् (anvadhāvat) - he pursued, he ran after

• वार्ष्णेयम् (vārṣṇeyam) - Krishna (scion of Vṛṣṇi)

• सर्वशस्त्रबृताम् (sarvaśastrabṛtām) - of all weapon-wielders

• वरम् (varam) - best, excellent, supreme

Words meanings and morphology

कृत्वा (kṛtvā) - having done, having made, having performed

(indeclinable)

absolutive

absolutive form of √kṛ (to do, make)

Root: kṛ (class 8)

प्रतिज्ञाम् (pratijñām) - vow, promise, oath

(noun)

Accusative, feminine, singular of pratijñā

pratijñā - vow, promise, oath, pledge

Prefix: prati

Root: jñā (class 9)

न (na) - not, no

(indeclinable)

अहत्वा (ahatvā) - without having killed

(indeclinable)

negative absolutive

negative absolutive of √han (to strike, kill)

Prefix: a

Root: han (class 2)

निवर्तिष्यामि (nivartiṣyāmi) - I will return

(verb)

1st person , singular, active, future (lṛṭ) of nivṛt

future tense

1st person singular future tense parasmaipada

Prefix: ni

Root: vṛt (class 1)

केशवम् (keśavam) - Krishna (Keśava)

(proper noun)

Accusative, masculine, singular of keśava

keśava - Keśava (an epithet of Vishnu/Krishna)

ततः (tataḥ) - then, thereupon, from that

(indeclinable)

अन्वधावत् (anvadhāvat) - he pursued, he ran after

(verb)

3rd person , singular, active, past imperfect (laṅ) of anudhāv

imperfect

3rd person singular imperfect parasmaipada

Prefix: anu

Root: dhāv (class 1)

वार्ष्णेयम् (vārṣṇeyam) - Krishna (scion of Vṛṣṇi)

(proper noun)

Accusative, masculine, singular of vārṣṇeya

vārṣṇeya - descendant of Vṛṣṇi (an epithet of Krishna)

सर्वशस्त्रबृताम् (sarvaśastrabṛtām) - of all weapon-wielders

(adjective)

Genitive, masculine, plural of sarvaśastrabṛt

sarvaśastrabṛt - weapon-wielder, one who bears all weapons

Compound type : tatpurusha (sarva+śastra+bhṛt)

• sarva – all, every
  adjective
• śastra – weapon
  noun (neuter)
• bhṛt – bearing, holding, maintaining (suffix)
  adjective
  Derived from root √bhṛ (to bear, carry)
  Root: bhṛ (class 1)

Note: modifies implied noun, 'among the best of'

वरम् (varam) - best, excellent, supreme

(adjective)

Accusative, masculine, singular of vara

vara - best, excellent, superior, boon

Note: modifies Vārṣṇeyam