महाभारतः mahābhārataḥ - book-3, chapter-240, verse-4

नियच्छैतां मतिं राजन्धर्मार्थसुखनाशिनीम् ।
यशःप्रतापधैर्यघ्नीं शत्रूणां हर्षवर्धनीम् ॥४॥

4. niyacchaitāṁ matiṁ rājandharmārthasukhanāśinīm ,
yaśaḥpratāpadhairyaghnīṁ śatrūṇāṁ harṣavardhanīm.

4. niyaccha etām matim rājan dharmārthasukhanāśinīm
yaśaḥpratāpadhairyaghnīm śatrūṇām harṣavardhanīm

4. O King, restrain this mindset of yours, which destroys righteousness (dharma), prosperity, and happiness; which annihilates fame, prowess, and courage; and which increases the joy of your enemies.

Words meanings summery:

• नियच्छ (niyaccha) - restrain, control, subdue

• एताम् (etām) - this

• मतिम् (matim) - mindset (mind, intellect, thought, intention)

• राजन् (rājan) - O King!

• धर्मार्थसुखनाशिनीम् (dharmārthasukhanāśinīm) - destroys righteousness (dharma), prosperity, and happiness (destroying righteousness, wealth, and happiness)

• यशःप्रतापधैर्यघ्नीम् (yaśaḥpratāpadhairyaghnīm) - annihilates fame, prowess, and courage (destroying fame, valor, and courage)

• शत्रूणाम् (śatrūṇām) - of enemies

• हर्षवर्धनीम् (harṣavardhanīm) - increases the joy (increasing joy, gladdening)

Words meanings and morphology

नियच्छ (niyaccha) - restrain, control, subdue

(verb)

2nd person , singular, active, imperative (loṭ) of yam

Imperative

2nd person singular Imperative active

Prefix: ni

Root: yam (class 1)

एताम् (etām) - this

(pronoun)

Accusative, feminine, singular of etas

etas - this

Pratipadika is etad

मतिम् (matim) - mindset (mind, intellect, thought, intention)

(noun)

Accusative, feminine, singular of mati

mati - mind, intellect, thought, intention, opinion

From root man 'to think' + -ti suffix

Root: man (class 4)

राजन् (rājan) - O King!

(noun)

Vocative, masculine, singular of rājan

rājan - king, ruler

Root: rāj (class 1)

धर्मार्थसुखनाशिनीम् (dharmārthasukhanāśinīm) - destroys righteousness (dharma), prosperity, and happiness (destroying righteousness, wealth, and happiness)

(adjective)

Accusative, feminine, singular of dharmārthasukhanāśinī

dharmārthasukhanāśinī - destroying dharma, artha, and sukha

Compound of dharma, artha, sukha, and nāśinī

Compound type : tatpuruṣa (dharma+artha+sukha+nāśinī)

• dharma – righteousness, duty, natural law, constitution
  noun (masculine)
  Root: dhṛ (class 1)
• artha – purpose, wealth, prosperity, meaning
  noun (masculine)
• sukha – happiness, joy, pleasure, comfort
  noun (neuter)
• nāśinī – destroying, perishing (feminine form)
  adjective (feminine)
  Agentive adjective/noun
  From root naś 'to perish, destroy' + -in suffix, feminine -ī
  Root: naś (class 4)

यशःप्रतापधैर्यघ्नीम् (yaśaḥpratāpadhairyaghnīm) - annihilates fame, prowess, and courage (destroying fame, valor, and courage)

(adjective)

Accusative, feminine, singular of yaśaḥpratāpadhairyaghnī

yaśaḥpratāpadhairyaghnī - destroying fame, glory, prowess, and courage

Compound of yaśas, pratāpa, dhairya, and ghnī

Compound type : tatpuruṣa (yaśas+pratāpa+dhairya+ghnī)

• yaśas – fame, glory, reputation
  noun (neuter)
• pratāpa – prowess, valor, majesty, heat
  noun (masculine)
  From root tap with upasarga pra
  Prefix: pra
  Root: tap (class 1)
• dhairya – courage, fortitude, firmness
  noun (neuter)
  From dhīra (firm) + -ya suffix
• ghnī – killing, destroying (feminine form)
  adjective (feminine)
  Agentive adjective/noun
  From root han 'to strike/kill' (ghna substitution) + -ī suffix for feminine
  Root: han (class 2)

शत्रूणाम् (śatrūṇām) - of enemies

(noun)

Genitive, masculine, plural of śatru

śatru - enemy, foe

Note: Possessive case for harṣavardhanīm

हर्षवर्धनीम् (harṣavardhanīm) - increases the joy (increasing joy, gladdening)

(adjective)

Accusative, feminine, singular of harṣavardhanī

harṣavardhanī - increasing joy, gladdening, causing happiness

Compound of harṣa and vardhanī

Compound type : tatpuruṣa (harṣa+vardhanī)

• harṣa – joy, delight, happiness
  noun (masculine)
  From root hṛṣ 'to be glad'
  Root: hṛṣ (class 1)
• vardhanī – increasing, causing to grow (feminine form)
  adjective (feminine)
  Agentive adjective/noun
  From root vṛdh 'to grow, increase' + -ana suffix, feminine -ī
  Root: vṛdh (class 1)