महाभारतः mahābhārataḥ - book-1, chapter-19, verse-12

ब्रह्मर्षिणा च तपता वर्षाणां शतमत्रिणा ।
अनासादितगाधं च पातालतलमव्ययम् ॥१२॥

12. brahmarṣiṇā ca tapatā varṣāṇāṁ śatamatriṇā ,
anāsāditagādhaṁ ca pātālatalamavyayam.

12. brahmarṣiṇā ca tapatā varṣāṇām śatam atriṇā
anāsāditagādham ca pātālatalam avyayam

12. And even the brahmin sage Atri, performing austerities for a hundred years, could not fathom its depths, reaching down to the imperishable realm of Pātāla.

Words meanings summery:

• ब्रह्मर्षिणा (brahmarṣiṇā) - by the sage (by the brahmin sage)

• च (ca) - and

• तपता (tapatā) - by the one engaged in severe austerities (by the one performing penance/austerity)

• वर्षाणाम् (varṣāṇām) - for (a period of) years (of years)

• शतम् (śatam) - a hundred

• अत्रिणा (atriṇā) - by the sage Atri (by Atri (a famous sage))

• अनासादितगाधम् (anāsāditagādham) - unfathomable, its bottom not reached (whose depth was not reached, unfathomable)

• च (ca) - and

• पातालतलम् (pātālatalam) - the lowest region of Pātāla (the bottom of Pātāla, the netherworld)

• अव्ययम् (avyayam) - eternal, immutable (imperishable, undecaying, unchangeable)

Words meanings and morphology

ब्रह्मर्षिणा (brahmarṣiṇā) - by the sage (by the brahmin sage)

(noun)

Instrumental, masculine, singular of brahmarṣi

brahmarṣi - brahmin sage, a sage of the highest order

Compound type : tatpurusha (brahman+ṛṣi)

• brahman – Brahmin, sacred knowledge, the Absolute
  noun (neuter)
• ṛṣi – sage, seer
  noun (masculine)

Note: Agrees with `atriṇā`.

च (ca) - and

(indeclinable)

तपता (tapatā) - by the one engaged in severe austerities (by the one performing penance/austerity)

(adjective)

Instrumental, masculine, singular of tapat

tapat - performing austerity, heating, shining

present active participle

from tap (to heat, perform penance)

Root: tap (class 1)

Note: Agrees with `atriṇā`.

वर्षाणाम् (varṣāṇām) - for (a period of) years (of years)

(noun)

Genitive, neuter, plural of varṣa

varṣa - rain, year

Note: Genitive plural, used with `śatam` to indicate duration ('for a hundred years').

शतम् (śatam) - a hundred

(noun)

Accusative, neuter, singular of śata

śata - hundred

Note: Accusative singular, used with genitive `varṣāṇām` to express 'a hundred years'.

अत्रिणा (atriṇā) - by the sage Atri (by Atri (a famous sage))

(noun)

Instrumental, masculine, singular of atri

atri - Atri (name of a famous Vedic sage)

Note: Agent of the action (implied 'could not fathom').

अनासादितगाधम् (anāsāditagādham) - unfathomable, its bottom not reached (whose depth was not reached, unfathomable)

(adjective)

Accusative, neuter, singular of anāsāditagādha

anāsāditagādha - whose depth is not reached

Compound type : bahuvrihi (an+āsādita+gādha)

• an – not
  prefix
• āsādita – reached, attained, acquired
  adjective (masculine)
  past passive participle
  from ā + sad (to sit, approach)
  Prefixes: ā+sam
  Root: sad (class 1)
• gādha – depth, ford, shallow
  noun (neuter)

Note: Bahuvrīhi compound, describes the ocean or Pātāla.

च (ca) - and

(indeclinable)

पातालतलम् (pātālatalam) - the lowest region of Pātāla (the bottom of Pātāla, the netherworld)

(noun)

Accusative, neuter, singular of pātālatala

pātālatala - the bottom of Pātāla, the netherworld

Compound type : tatpurusha (pātāla+tala)

• pātāla – the netherworld, one of the seven regions below the earth
  noun (neuter)
• tala – surface, bottom, sole, region
  noun (neuter)

Note: Refers to the deepest part of the ocean.

अव्ययम् (avyayam) - eternal, immutable (imperishable, undecaying, unchangeable)

(adjective)

Accusative, neuter, singular of avyaya

avyaya - imperishable, undecaying, immutable, eternal

from a + vyaya (perishable)

Compound type : bahuvrihi (a+vyaya)

• a – not
  prefix
• vyaya – perishing, spending, decay
  noun (masculine)
  action noun
  from vi + i (to go)
  Prefix: vi
  Root: i (class 2)

Note: Agrees with `pātālatalam`.