महाभारतः mahābhārataḥ - book-12, chapter-255, verse-18

क्षेत्रक्षेत्रज्ञतत्त्वज्ञाः स्वयज्ञपरिनिष्ठिताः ।
ब्राह्मं वेदमधीयन्तस्तोषयन्त्यमरानपि ॥१८॥

18. kṣetrakṣetrajñatattvajñāḥ svayajñapariniṣṭhitāḥ ,
brāhmaṁ vedamadhīyantastoṣayantyamarānapi.

18. kṣetrakṣetrajñatattvajñāḥ svayajñapariniṣṭhitāḥ
brāhmam vedam adhīyantaḥ toṣayanti amarān api

18. kṣetrakṣetrajñatattvajñāḥ svayajñapariniṣṭhitāḥ
brāhmam vedam adhīyantaḥ amarān api toṣayanti

18. Those who understand the true nature of the field (kṣetra) and the knower of the field (kṣetrajña), and who are firmly established in their own Vedic rituals (yajña), please even the gods by diligently studying the Vedic knowledge pertaining to Brahman (brahman).

Words meanings summery:

• क्षेत्रक्षेत्रज्ञतत्त्वज्ञाः (kṣetrakṣetrajñatattvajñāḥ) - knowers of the truth of the field (kṣetra) and the knower of the field (kṣetrajña)

• स्वयज्ञपरिनिष्ठिताः (svayajñapariniṣṭhitāḥ) - firmly established in their own sacrifices (yajña)

• ब्राह्मम् (brāhmam) - relating to Brahman (brahman), divine, sacred

• वेदम् (vedam) - Veda, sacred knowledge, scripture

• अधीयन्तः (adhīyantaḥ) - studying, reciting, learning

• तोषयन्ति (toṣayanti) - they please, they satisfy

• अमरान् (amarān) - immortals, gods

• अपि (api) - even, also, too

Words meanings and morphology

क्षेत्रक्षेत्रज्ञतत्त्वज्ञाः (kṣetrakṣetrajñatattvajñāḥ) - knowers of the truth of the field (kṣetra) and the knower of the field (kṣetrajña)

(adjective)

Nominative, masculine, plural of kṣetrakṣetrajñatattvajña

kṣetrakṣetrajñatattvajña - knowers of the reality of the field and the knower of the field

Compound type : tatpurusha (kṣetra+kṣetrajña+tattva+jña)

• kṣetra – field, body, sacred place, sphere of action
  noun (neuter)
• kṣetrajña – knower of the field, soul, spirit, individual self
  noun (masculine)
  From kṣetra + root jñā (to know).
  Root: jñā (class 9)
• tattva – truth, reality, essence, principle, true nature
  noun (neuter)
  From tad (that) + tva (suffix for abstract noun).
• jña – knower, understanding
  adjective (masculine)
  From root jñā (to know).
  Root: jñā (class 9)

Note: Qualifies the implied subject 'they'.

स्वयज्ञपरिनिष्ठिताः (svayajñapariniṣṭhitāḥ) - firmly established in their own sacrifices (yajña)

(adjective)

Nominative, masculine, plural of svayajñapariniṣṭhita

svayajñapariniṣṭhita - steadfast in one's own sacrifices

Compound type : tatpurusha (sva+yajña+pariniṣṭhita)

• sva – one's own, self
  pronoun (masculine)
• yajña – sacrifice, ritual, worship
  noun (masculine)
  From root yaj (to sacrifice).
  Root: yaj (class 1)
• pariniṣṭhita – firmly established, steadfast, accomplished, perfected
  adjective (masculine)
  Past Passive Participle
  From pari + ni + root sthā (to stand).
  Prefixes: pari+ni
  Root: sthā (class 1)

Note: Qualifies the implied subject 'they'.

ब्राह्मम् (brāhmam) - relating to Brahman (brahman), divine, sacred

(adjective)

Accusative, neuter, singular of brāhma

brāhma - relating to Brahman (brahman), belonging to Brahmā, sacred, divine

Derivative of brahman.

Note: Object of adhīyantaḥ.

वेदम् (vedam) - Veda, sacred knowledge, scripture

(noun)

Accusative, masculine, singular of veda

veda - Veda, sacred knowledge, scripture, knowledge

From root vid (to know).

Root: vid (class 2)

Note: Object of adhīyantaḥ.

अधीयन्तः (adhīyantaḥ) - studying, reciting, learning

(adjective)

Nominative, masculine, plural of adhīyamāna

adhīyamāna - studying, learning, being read

Present Middle Participle, Nominative Masculine Plural

From adhi + root i (to go), used in the sense of 'to study'. adhi + i forms adhī.

Prefix: adhi

Root: i (class 2)

Note: Functions adverbially to describe the action of pleasing.

तोषयन्ति (toṣayanti) - they please, they satisfy

(verb)

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

Causative Present active indicative, 3rd person plural

Root tuṣ (to be pleased), causative stem toṣaya.

Root: tuṣ (class 4)

Note: The subject 'they' is implied from the preceding adjectives.

अमरान् (amarān) - immortals, gods

(noun)

Accusative, masculine, plural of amara

amara - immortal, god, deity

From a- (negation) + mara (mortal).

Compound type : nañ-tatpurusha (a+mara)

• a – not, un-
  indeclinable
• mara – mortal, dying
  adjective (masculine)
  From root mṛ (to die).
  Root: mṛ (class 6)

Note: Direct object.

अपि (api) - even, also, too

(indeclinable)