महाभारतः mahābhārataḥ - book-3, chapter-209, verse-18

ब्रह्मचारी यतात्मा च सततं विपुलव्रतः ।
ब्राह्मणाः पूजयन्त्येनं पाकयज्ञेषु पावकम् ॥१८॥

18. brahmacārī yatātmā ca satataṁ vipulavrataḥ ,
brāhmaṇāḥ pūjayantyenaṁ pākayajñeṣu pāvakam.

18. brahmacārī yatātmā ca satatam vipulavrataḥ
brāhmaṇāḥ pūjayanti enam pākayajñeṣu pāvakam

18. Brāhmaṇas always worship as a purifier (pāvaka) in domestic ritual sacrifices (pākayajña) that person who is a celibate student (brahmacārī), self-controlled (ātman), and constantly dedicated to extensive vows.

Words meanings summery:

• ब्रह्मचारी (brahmacārī) - a celibate student of sacred knowledge (celibate student, one who observes a religious vow)

• यतात्मा (yatātmā) - one who has controlled his inner self (ātman) (self-controlled, whose self is controlled)

• च (ca) - and (and, also)

• सततम् (satatam) - constantly (constantly, always, perpetually)

• विपुलव्रतः (vipulavrataḥ) - one who constantly observes extensive vows (having extensive vows, observing great vows)

• ब्राह्मणाः (brāhmaṇāḥ) - Brāhmaṇa priests (Brāhmaṇas, Brahmins)

• पूजयन्ति (pūjayanti) - they worship, revere (they worship, they honor)

• एनम् (enam) - him (the brahmacārī) (him, this one)

• पाकयज्ञेषु (pākayajñeṣu) - in domestic ritual sacrifices (in domestic sacrifices, in small offerings)

• पावकम् (pāvakam) - as a purifier, referring to fire itself (purifier, fire, Agni)

Words meanings and morphology

ब्रह्मचारी (brahmacārī) - a celibate student of sacred knowledge (celibate student, one who observes a religious vow)

(noun)

Nominative, masculine, singular of brahmacārin

brahmacārin - celibate student, one who practices Brahman-conduct

from brahman + cārin (doer/practicer)

Compound type : tatpuruṣa (brahman+cārin)

• brahman – sacred utterance, Veda, ultimate reality (brahman), priest (brahmin)
  noun (neuter)
• cārin – moving, walking, practicing, following
  adjective (masculine)
  from √car (to move, practice) + -in (agent suffix)
  Root: car (class 1)

यतात्मा (yatātmā) - one who has controlled his inner self (ātman) (self-controlled, whose self is controlled)

(adjective)

Nominative, masculine, singular of yatātman

yatātman - self-controlled, having a subdued self

Compound type : bahuvrīhi (yata+ātman)

• yata – controlled, restrained, subdued
  adjective (masculine)
  Past Passive Participle
  from √yam (to restrain, control)
  Root: yam (class 1)
• ātman – self, soul, essence, spirit
  noun (masculine)

च (ca) - and (and, also)

(indeclinable)

सततम् (satatam) - constantly (constantly, always, perpetually)

(indeclinable)

Note: Often takes an adverbial accusative form.

विपुलव्रतः (vipulavrataḥ) - one who constantly observes extensive vows (having extensive vows, observing great vows)

(adjective)

Nominative, masculine, singular of vipulavrata

vipulavrata - having great or extensive vows

Compound type : bahuvrīhi (vipula+vrata)

• vipula – large, extensive, abundant
  adjective (masculine)
• vrata – vow, sacred observance, religious practice
  noun (neuter)

ब्राह्मणाः (brāhmaṇāḥ) - Brāhmaṇa priests (Brāhmaṇas, Brahmins)

(noun)

Nominative, masculine, plural of brāhmaṇa

brāhmaṇa - a Brahmin, belonging to the priestly class, pertaining to Brahman

पूजयन्ति (pūjayanti) - they worship, revere (they worship, they honor)

(verb)

3rd person , plural, active, present (laṭ) of pūj

Root: pūj (class 10)

एनम् (enam) - him (the brahmacārī) (him, this one)

(pronoun)

Accusative, masculine, singular of ena

ena - this, that, him, her, it (demonstrative pronoun, used for emphasis or reference)

पाकयज्ञेषु (pākayajñeṣu) - in domestic ritual sacrifices (in domestic sacrifices, in small offerings)

(noun)

Locative, masculine, plural of pākayajña

pākayajña - domestic sacrifice, small offering, simple ritual (as opposed to grand Vedic yajña)

Compound type : tatpuruṣa (pāka+yajña)

• pāka – cooking, ripening, simple, immature, domestic
  noun (masculine)
• yajña – sacrifice, worship, ritual, offering
  noun (masculine)
  from √yaj (to sacrifice, worship)
  Root: yaj (class 1)

पावकम् (pāvakam) - as a purifier, referring to fire itself (purifier, fire, Agni)

(noun)

Accusative, masculine, singular of pāvaka

pāvaka - purifier, fire, clean, pure

from √pū (to purify) + -aka (agent suffix)

Root: pū (class 1)