महाभारतः mahābhārataḥ - book-3, chapter-186, verse-20

तथा वर्षसहस्रे द्वे द्वापरं परिमाणतः ।
तस्यापि द्विशती संध्या संध्यांशश्च ततः परम् ॥२०॥

20. tathā varṣasahasre dve dvāparaṁ parimāṇataḥ ,
tasyāpi dviśatī saṁdhyā saṁdhyāṁśaśca tataḥ param.

20. tathā varṣasahasre dve dvāparam parimāṇataḥ tasya
api dviśatī sandhyā sandhyāṃśaḥ ca tataḥ param

20. Similarly, two thousand years is the measure for Dvāpara (Yuga). Its sandhyā (transition period) is two hundreds (of years), and its sandhyāṃśa (concluding portion) is likewise that much thereafter.

Words meanings summery:

• तथा (tathā) - similarly, thus, so

• वर्षसहस्रे (varṣasahasre) - two thousand years

• द्वे (dve) - two

• द्वापरम् (dvāparam) - Refers to the Dvāpara Yuga, the third of the four ages, having a core duration of two thousand years. (Dvāpara (Yuga))

• परिमाणतः (parimāṇataḥ) - by measure, in terms of duration, by calculation

• तस्य (tasya) - its, of that

• अपि (api) - also, even, moreover

• द्विशती (dviśatī) - Refers to two hundred (years), which is the specific duration for the sandhyā period of Dvāpara Yuga. (two hundreds, two hundred (years))

• सन्ध्या (sandhyā) - Refers to the specific pre-dawn transitional period of a Yuga. (transition period, twilight, junction period)

• सन्ध्यांशः (sandhyāṁśaḥ) - Refers to the specific post-dusk transitional period of a Yuga. (part of the sandhyā, concluding portion of the transition period)

• च (ca) - and, also

• ततः (tataḥ) - thereafter, from that, then

• परम् (param) - Used adverbially to mean 'after that' or 'subsequently'. (beyond, after, further, supreme)

Words meanings and morphology

तथा (tathā) - similarly, thus, so

(indeclinable)

Note: Connects this statement to the preceding descriptions of Yuga durations.

वर्षसहस्रे (varṣasahasre) - two thousand years

(noun)

Nominative, neuter, dual of varṣasahasra

varṣasahasra - thousand years

Compound type : Tatpuruṣa (varṣa+sahasra)

• varṣa – year, rain
  noun (neuter)
• sahasra – thousand
  noun (neuter)

Note: Used in dual form to mean 'two thousands'.

द्वे (dve) - two

(numeral)

Note: Modifies 'varṣasahasre'.

द्वापरम् (dvāparam) - Refers to the Dvāpara Yuga, the third of the four ages, having a core duration of two thousand years. (Dvāpara (Yuga))

(proper noun)

Nominative, neuter, singular of dvāpara

dvāpara - Dvāpara Yuga

परिमाणतः (parimāṇataḥ) - by measure, in terms of duration, by calculation

(indeclinable)

Formed with suffix -tas from 'parimāṇa'

Note: Adverbial usage derived from a noun, indicating 'according to measure'.

तस्य (tasya) - its, of that

(pronoun)

Genitive, neuter, singular of tad

tad - that, that one

Note: Refers to the Dvāpara Yuga.

अपि (api) - also, even, moreover

(indeclinable)

Note: Emphasizes similarity to the previous Yuga descriptions.

द्विशती (dviśatī) - Refers to two hundred (years), which is the specific duration for the sandhyā period of Dvāpara Yuga. (two hundreds, two hundred (years))

(noun)

Nominative, feminine, singular of dviśata

dviśata - two hundred

Compound of 'dvi' (two) and 'śata' (hundred)

Compound type : Tatpuruṣa (dvi+śata)

• dvi – two
  numeral
• śata – hundred
  noun (neuter)

Note: Feminine form, agrees with 'sandhyā'.

सन्ध्या (sandhyā) - Refers to the specific pre-dawn transitional period of a Yuga. (transition period, twilight, junction period)

(noun)

Nominative, feminine, singular of sandhyā

sandhyā - transition period, twilight, junction period

सन्ध्यांशः (sandhyāṁśaḥ) - Refers to the specific post-dusk transitional period of a Yuga. (part of the sandhyā, concluding portion of the transition period)

(noun)

Nominative, masculine, singular of sandhyāṃśa

sandhyāṁśa - part of the sandhyā, concluding portion of the transition period

Compound type : Tatpuruṣa (sandhyā+aṃśa)

• sandhyā – transition period, twilight, junction period
  noun (feminine)
• aṃśa – part, share, portion
  noun (masculine)

च (ca) - and, also

(indeclinable)

Note: Conjunction.

ततः (tataḥ) - thereafter, from that, then

(indeclinable)

Formed with suffix -tas, indicating source or sequence.

परम् (param) - Used adverbially to mean 'after that' or 'subsequently'. (beyond, after, further, supreme)

(indeclinable)

Note: Here functioning as an adverb.