महाभारतः mahābhārataḥ - book-3, chapter-148, verse-33

तामसं युगमासाद्य कृष्णो भवति केशवः ।
वेदाचाराः प्रशाम्यन्ति धर्मयज्ञक्रियास्तथा ॥३३॥

33. tāmasaṁ yugamāsādya kṛṣṇo bhavati keśavaḥ ,
vedācārāḥ praśāmyanti dharmayajñakriyāstathā.

33. tāmasam yugam āsādya kṛṣṇaḥ bhavati keśavaḥ
vedācārāḥ praśāmyanti dharmayajñakriyāḥ tathā

33. tāmasam yugam āsādya keśavaḥ kṛṣṇaḥ bhavati
vedācārāḥ tathā dharmayajñakriyāḥ praśāmyanti

33. Upon the arrival of the Tāmasic age, Krishna (Keśava) becomes dark [in manifestation, indicating a decline]. Vedic practices (vedācārāḥ) diminish, and likewise, the activities related to natural law (dharma) and Vedic rituals (yajña) cease.

Words meanings summery:

• तामसम् (tāmasam) - dark, ignorant, dull, related to tamas

• युगम् (yugam) - age, epoch, era

• आसाद्य (āsādya) - having reached, having obtained, having approached

• कृष्णः (kṛṣṇaḥ) - Lord Krishna, representing a divine manifestation (Krishna, dark, black)

• भवति (bhavati) - becomes, is, happens

• केशवः (keśavaḥ) - Keśava (an epithet of Vishnu/Krishna)

• वेदाचाराः (vedācārāḥ) - Vedic customs, practices according to the Vedas

• प्रशाम्यन्ति (praśāmyanti) - they cease, they diminish, they calm down

• धर्मयज्ञक्रियाः (dharmayajñakriyāḥ) - activities related to natural law and Vedic rituals

• तथा (tathā) - thus, so, likewise, and also

Words meanings and morphology

तामसम् (tāmasam) - dark, ignorant, dull, related to tamas

(adjective)

Accusative, neuter, singular of tāmasa

tāmasa - relating to tamas (the quality of inertia, ignorance, darkness); dark, ignorant

Derived from tamas (darkness, inertia)

युगम् (yugam) - age, epoch, era

(noun)

Accusative, neuter, singular of yuga

yuga - age, epoch, era; yoke

आसाद्य (āsādya) - having reached, having obtained, having approached

(indeclinable)

Absolutive (Gerund)

Derived from root sad with upasarga ā, forming an absolutive.

Prefix: ā

Root: sad (class 1)

कृष्णः (kṛṣṇaḥ) - Lord Krishna, representing a divine manifestation (Krishna, dark, black)

(proper noun)

Nominative, masculine, singular of kṛṣṇa

kṛṣṇa - dark, black; Krishna (a specific deity)

भवति (bhavati) - becomes, is, happens

(verb)

3rd person , singular, active, present indicative (laṭ) of bhū

Root: bhū (class 1)

केशवः (keśavaḥ) - Keśava (an epithet of Vishnu/Krishna)

(proper noun)

Nominative, masculine, singular of keśava

keśava - Keśava (an epithet of Vishnu or Krishna, often interpreted as 'one with beautiful hair' or 'killer of the demon Keśī')

वेदाचाराः (vedācārāḥ) - Vedic customs, practices according to the Vedas

(noun)

Nominative, masculine, plural of vedācāra

vedācāra - Vedic custom, practice according to the Vedas

Compound type : tatpuruṣa (veda+ācāra)

• veda – Veda (sacred knowledge); knowledge
  noun (masculine)
• ācāra – custom, practice, conduct
  noun (masculine)

प्रशाम्यन्ति (praśāmyanti) - they cease, they diminish, they calm down

(verb)

3rd person , plural, active, present indicative (laṭ) of praśam

Derived from root śam with upasarga pra.

Prefix: pra

Root: śam (class 4)

धर्मयज्ञक्रियाः (dharmayajñakriyāḥ) - activities related to natural law and Vedic rituals

(noun)

Nominative, feminine, plural of dharmayajñakriyā

dharmayajñakriyā - activities of dharma and yajña

Compound type : dvandva-tatpuruṣa (dharma+yajña+kriyā)

• dharma – natural law, duty, righteousness, constitution
  noun (masculine)
• yajña – Vedic ritual, sacrifice
  noun (masculine)
• kriyā – action, activity, performance
  noun (feminine)

तथा (tathā) - thus, so, likewise, and also

(indeclinable)