महाभारतः mahābhārataḥ - book-12, chapter-2, verse-13

ब्रह्मास्त्रं ब्राह्मणो विद्याद्यथावच्चरितव्रतः ।
क्षत्रियो वा तपस्वी यो नान्यो विद्यात्कथंचन ॥१३॥

13. brahmāstraṁ brāhmaṇo vidyādyathāvaccaritavrataḥ ,
kṣatriyo vā tapasvī yo nānyo vidyātkathaṁcana.

13. brahmāstram brāhmaṇaḥ vidyāt yathāvat caritavrataḥ
kṣatriyaḥ vā tapasvī yaḥ na anyaḥ vidyāt kathaṃcana

13. yathāvat caritavrataḥ brāhmaṇaḥ brahmāstram vidyāt
vā yaḥ tapasvī kṣatriyaḥ na anyaḥ kathaṃcana vidyāt

13. Only a Brahmin who has properly fulfilled his vows, or a Kṣatriya who is an ascetic (tapasvī), should know the Brahmastra (brahmāstra). No other person should ever learn it by any means.

Words meanings summery:

• ब्रह्मास्त्रम् (brahmāstram) - the divine weapon Brahmastra

• ब्राह्मणः (brāhmaṇaḥ) - a Brahmin, one belonging to the priestly class

• विद्यात् (vidyāt) - (a Brahmin) should know (should know, should learn)

• यथावत् (yathāvat) - properly, correctly, as it should be

• चरितव्रतः (caritavrataḥ) - one who has observed vows, one who has fulfilled sacred duties

• क्षत्रियः (kṣatriyaḥ) - a Kshatriya, a member of the warrior class

• वा (vā) - or, either

• तपस्वी (tapasvī) - an ascetic, one who practices austerities (tapas)

• यः (yaḥ) - (the Kshatriya) who (who, which)

• न (na) - not, no

• अन्यः (anyaḥ) - no other person (another, other)

• विद्यात् (vidyāt) - (no other person) should know (should know, should learn)

• कथंचन (kathaṁcana) - by any means, in any way, somehow or other

Words meanings and morphology

ब्रह्मास्त्रम् (brahmāstram) - the divine weapon Brahmastra

(noun)

Accusative, neuter, singular of brahmāstra

brahmāstra - the Brahmastra (a divine weapon, lit. 'Brahma's weapon')

Compound type : tatpurusha (brahman+astra)

• brahman – Brahma (the creator deity), sacred knowledge, ultimate reality
  proper noun (masculine)
• astra – weapon, missile
  noun (neuter)

ब्राह्मणः (brāhmaṇaḥ) - a Brahmin, one belonging to the priestly class

(noun)

Nominative, masculine, singular of brāhmaṇa

brāhmaṇa - a Brahmin (member of the priestly class), relating to Brahma

विद्यात् (vidyāt) - (a Brahmin) should know (should know, should learn)

(verb)

3rd person , singular, active, optative (liṅ) of vid

Optative mood, 3rd person singular

Optative form of root vid (class 2)

Root: vid (class 2)

यथावत् (yathāvat) - properly, correctly, as it should be

(indeclinable)

चरितव्रतः (caritavrataḥ) - one who has observed vows, one who has fulfilled sacred duties

(adjective)

Nominative, masculine, singular of caritavrata

caritavrata - one who has observed vows, one who has performed sacred duties (lit. 'whose vows have been performed')

Compound type : bahuvrihi (carita+vrata)

• carita – performed, observed, practiced
  adjective (neuter)
  Past Passive Participle
  Derived from root car (to move, perform)
  Root: car (class 1)
• vrata – vow, sacred duty, religious observance
  noun (neuter)

क्षत्रियः (kṣatriyaḥ) - a Kshatriya, a member of the warrior class

(noun)

Nominative, masculine, singular of kṣatriya

kṣatriya - a Kshatriya (member of the warrior/ruling class), belonging to the ruling power

वा (vā) - or, either

(indeclinable)

तपस्वी (tapasvī) - an ascetic, one who practices austerities (tapas)

(adjective)

Nominative, masculine, singular of tapasvin

tapasvin - an ascetic, one who practices austerities (tapas), devoted to penance

Possessive suffix -vin added to tapas

यः (yaḥ) - (the Kshatriya) who (who, which)

(pronoun)

Nominative, masculine, singular of yad

yad - who, which, what

न (na) - not, no

(indeclinable)

अन्यः (anyaḥ) - no other person (another, other)

(pronoun)

Nominative, masculine, singular of anya

anya - other, another, different

विद्यात् (vidyāt) - (no other person) should know (should know, should learn)

(verb)

3rd person , singular, active, optative (liṅ) of vid

Optative mood, 3rd person singular

Optative form of root vid (class 2)

Root: vid (class 2)

कथंचन (kathaṁcana) - by any means, in any way, somehow or other

(indeclinable)