महाभारतः mahābhārataḥ - book-3, chapter-259, verse-16

अतिष्ठदेकपादेन सहस्रं परिवत्सरान् ।
वायुभक्षो दशग्रीवः पञ्चाग्निः सुसमाहितः ॥१६॥

16. atiṣṭhadekapādena sahasraṁ parivatsarān ,
vāyubhakṣo daśagrīvaḥ pañcāgniḥ susamāhitaḥ.

16. atiṣṭhat ekapādena sahasram parivatsarān
vāyubhakṣaḥ daśagrīvaḥ pañcāgniḥ susamāhitaḥ

16. Daśagrīva stood on one foot for a thousand years, subsisting only on air, surrounded by five fires, and completely absorbed in his ascetic practice.

Words meanings summery:

• अतिष्ठत् (atiṣṭhat) - stood, remained, performed, undertook

• एकपादेन (ekapādena) - by one foot, on one leg

• सहस्रम् (sahasram) - a thousand (of years) (a thousand)

• परिवत्सरान् (parivatsarān) - years

• वायुभक्षः (vāyubhakṣaḥ) - subsisting on air, air-eater

• दशग्रीवः (daśagrīvaḥ) - Daśagrīva (Rāvaṇa) (Daśagrīva)

• पञ्चाग्निः (pañcāgniḥ) - practicing the five-fire austerity (surrounded by five fires (a form of asceticism))

• सुसमाहितः (susamāhitaḥ) - deeply absorbed in ascetic practice (well-concentrated, perfectly absorbed, composed)

Words meanings and morphology

अतिष्ठत् (atiṣṭhat) - stood, remained, performed, undertook

(verb)

3rd person , singular, active, Past Imperfect (laṅ) of sthā

Past Imperfect

Root sthā (to stand), Parasmaipada, 3rd person singular, augment 'a' added before the root, 'śap' infix 'a', 'ṭ' for 't' due to 'ṣ'.

Prefix: ati

Root: sthā (class 1)

एकपादेन (ekapādena) - by one foot, on one leg

(noun)

Instrumental, masculine, singular of ekapāda

ekapāda - one-footed, having one foot

Compound type : Bahuvrīhi (eka+pāda)

• eka – one, single, unique
  numeral adjective (masculine)
• pāda – foot, leg, quarter
  noun (masculine)

सहस्रम् (sahasram) - a thousand (of years) (a thousand)

(noun)

Accusative, neuter, singular of sahasra

sahasra - thousand, a multitude

Note: Indicates duration when in accusative case.

परिवत्सरान् (parivatsarān) - years

(noun)

Accusative, masculine, plural of parivatsara

parivatsara - a year, a full year

Note: Indicates duration when in accusative case.

वायुभक्षः (vāyubhakṣaḥ) - subsisting on air, air-eater

(adjective)

Nominative, masculine, singular of vāyubhakṣa

vāyubhakṣa - living on air, eating air (as an ascetic practice)

Compound type : Bahuvrīhi (vāyu+bhakṣa)

• vāyu – wind, air, breath
  noun (masculine)
• bhakṣa – food, eating, substance
  noun (masculine)
  Derived from the root bhakṣ (to eat).
  Root: bhakṣ (class 10)

दशग्रीवः (daśagrīvaḥ) - Daśagrīva (Rāvaṇa) (Daśagrīva)

(proper noun)

Nominative, masculine, singular of daśagrīva

daśagrīva - ten-necked (epithet of Rāvaṇa)

Compound type : Bahuvrīhi (daśa+grīva)

• daśa – ten
  numeral adjective
• grīva – neck
  noun (feminine)

पञ्चाग्निः (pañcāgniḥ) - practicing the five-fire austerity (surrounded by five fires (a form of asceticism))

(adjective)

Nominative, masculine, singular of pañcāgni

pañcāgni - five fires (referring to the ascetic practice where one sits surrounded by four fires, with the sun as the fifth)

Compound type : Bahuvrīhi (pañca+agni)

• pañca – five
  numeral adjective
• agni – fire, sacred fire
  noun (masculine)

Note: Refers to the ascetic practice of pañcāgni tapas (austerity of five fires).

सुसमाहितः (susamāhitaḥ) - deeply absorbed in ascetic practice (well-concentrated, perfectly absorbed, composed)

(participle adjective)