महाभारतः mahābhārataḥ - book-3, chapter-186, verse-53

भवन्ति षोडशे वर्षे नराः पलितिनस्तथा ।
आयुःक्षयो मनुष्याणां क्षिप्रमेव प्रपद्यते ॥५३॥

53. bhavanti ṣoḍaśe varṣe narāḥ palitinastathā ,
āyuḥkṣayo manuṣyāṇāṁ kṣiprameva prapadyate.

53. bhavanti ṣoḍaśe varṣe narāḥ palitinaḥ tathā
āyuḥkṣayaḥ manuṣyāṇām kṣipram eva prapadyate

53. Men become grey-haired by their sixteenth year. Thus, the decline of human lifespan quickly occurs.

Words meanings summery:

• भवन्ति (bhavanti) - become (they are, they become, they exist)

• षोडशे (ṣoḍaśe) - in the sixteenth (in the sixteenth, on the sixteenth)

• वर्षे (varṣe) - in the year (in the year, in the rains)

• नराः (narāḥ) - men (men, people, humans)

• पलितिनः (palitinaḥ) - grey-haired (grey-haired, having grey hair, old)

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

• आयुःक्षयः (āyuḥkṣayaḥ) - decline of lifespan (decay of life, destruction of life, decrease of life)

• मनुष्याणाम् (manuṣyāṇām) - of human (of humans, of men, of people)

• क्षिप्रम् (kṣipram) - quickly (quickly, swiftly, immediately)

• एव (eva) - indeed (indeed, just, only, very)

• प्रपद्यते (prapadyate) - occurs (approaches, obtains, reaches, occurs)

Words meanings and morphology

भवन्ति (bhavanti) - become (they are, they become, they exist)

(verb)

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

Root: bhū (class 1)

षोडशे (ṣoḍaśe) - in the sixteenth (in the sixteenth, on the sixteenth)

(adjective)

Locative, neuter, singular of ṣoḍaśa

ṣoḍaśa - sixteenth

वर्षे (varṣe) - in the year (in the year, in the rains)

(noun)

Locative, neuter, singular of varṣa

varṣa - year, rain, rainy season

Root: vṛṣ (class 1)

नराः (narāḥ) - men (men, people, humans)

(noun)

Nominative, masculine, plural of nara

nara - man, person, human

Root: nṛ

पलितिनः (palitinaḥ) - grey-haired (grey-haired, having grey hair, old)

(adjective)

Nominative, masculine, plural of palitin

palitin - grey-haired, old

derived from palita (grey hair) + possessive suffix -in

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

(indeclinable)

आयुःक्षयः (āyuḥkṣayaḥ) - decline of lifespan (decay of life, destruction of life, decrease of life)

(noun)

Nominative, masculine, singular of āyuḥkṣaya

āyuḥkṣaya - decay of life, loss of life, decrease of life

Compound type : tatpurusha (āyus+kṣaya)

• āyus – life, vital power, duration of life
  noun (neuter)
• kṣaya – loss, decay, destruction, decrease
  noun (masculine)
  derived from root kṣi (to destroy, diminish)
  Root: kṣi (class 5)

मनुष्याणाम् (manuṣyāṇām) - of human (of humans, of men, of people)

(noun)

Genitive, masculine, plural of manuṣya

manuṣya - human being, man, person

Root: man (class 4)

क्षिप्रम् (kṣipram) - quickly (quickly, swiftly, immediately)

(indeclinable)

Root: kṣip (class 6)

Note: Used adverbially as an accusative singular neuter adjective.

एव (eva) - indeed (indeed, just, only, very)

(indeclinable)

प्रपद्यते (prapadyate) - occurs (approaches, obtains, reaches, occurs)

(verb)

3rd person , singular, middle, present indicative (laṭ) of pr-pad

Prefix: pra

Root: pad (class 4)