योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-123, verse-16

विहगाश्वासतत्त्वज्ञः शाल्मलिद्वीपशाल्मलौ ।
पश्चिमः पक्षिणीनीडे क्रीडया न्यवसत्समाः ॥ १६ ॥

vihagāśvāsatattvajñaḥ śālmalidvīpaśālmalau ,
paścimaḥ pakṣiṇīnīḍe krīḍayā nyavasatsamāḥ 16

16. vihagāśvāsatattvajñaḥ śālmalīdvīpaśālmalau
paścimaḥ pakṣiṇīnīḍe krīḍayā nyavasat samāḥ

16. (saḥ) vihagāśvāsatattvajñaḥ paścimaḥ krīḍayā
śālmalīdvīpaśālmalau pakṣiṇīnīḍe samāḥ nyavasat

16. He, a knower of the true nature of bird comfort, in his last existence, resided playfully for years in a female bird's nest within a silk-cotton tree (śālmalī) on Śālmalī Island.

Words meanings summery:

• विहगाश्वासतत्त्वज्ञः (vihagāśvāsatattvajñaḥ) - a knower of the true nature of bird comfort (one who knows the true nature of bird comfort/respiration)

• शाल्मलीद्वीपशाल्मलौ (śālmalīdvīpaśālmalau) - in a silk-cotton tree (śālmalī) on Śālmalī Island (in a silk-cotton tree on Śālmalī Island)

• पश्चिमः (paścimaḥ) - in his last (existence/incarnation) (western, last, subsequent)

• पक्षिणीनीडे (pakṣiṇīnīḍe) - in a female bird's nest

• क्रीडया (krīḍayā) - playfully (playfully, by sport, with play)

• न्यवसत् (nyavasat) - he resided (he dwelt, he resided)

• समाः (samāḥ) - for years (years)

Words meanings and morphology

विहगाश्वासतत्त्वज्ञः (vihagāśvāsatattvajñaḥ) - a knower of the true nature of bird comfort (one who knows the true nature of bird comfort/respiration)

(noun)

Nominative, masculine, singular of vihagāśvāsatattvajña

vihagāśvāsatattvajña - knower of the true nature of bird's breathing/comfort

Compound: vihaga (bird) + āśvāsa (comfort/breathing) + tattvajña (knower of truth/essence)

Compound type : tatpuruṣa (vihaga+āśvāsa+tattvajña)

• vihaga – bird
  noun (masculine)
  Literally 'sky-goer', from vih (sky) + ga (goer)
  Root: gam (class 1)
• āśvāsa – comfort, relief, breathing, respiration
  noun (masculine)
  Action noun from ā-√śvas (to breathe, sigh)
  From root śvas (to breathe) with upasarga ā
  Prefix: ā
  Root: śvas (class 2)
• tattvajña – knower of the truth/essence
  noun (masculine)
  Agent noun from tattva (truth/essence) + jña (knower)
  Compound: tattva (truth/essence) + jña (knower, from root jñā)
  Root: jñā (class 9)

Note: An adjective describing the implicit subject.

शाल्मलीद्वीपशाल्मलौ (śālmalīdvīpaśālmalau) - in a silk-cotton tree (śālmalī) on Śālmalī Island (in a silk-cotton tree on Śālmalī Island)

(noun)

Locative, masculine, singular of śālmalīdvīpaśālmala

śālmalīdvīpaśālmala - a silk-cotton tree of Śālmalī Island

Compound: Śālmalīdvīpa (Śālmalī Island) + śālmala (silk-cotton tree)

Compound type : tatpuruṣa (śālmalīdvīpa+śālmala)

• śālmalīdvīpa – Śālmalī Island (one of the seven mythical islands)
  proper noun (masculine)
  Compound: śālmalī (silk-cotton tree) + dvīpa (island)
• śālmala – silk-cotton tree
  noun (masculine)
  Related to śālmalī

Note: Compound expressing location 'in the tree on the island'.

पश्चिमः (paścimaḥ) - in his last (existence/incarnation) (western, last, subsequent)

(adjective)

Nominative, masculine, singular of paścima

paścima - western, last, hindmost, ultimate

Superlative suffix -ima from paścā (behind)

Note: Modifies the implicit subject, referring to his state or incarnation.

पक्षिणीनीडे (pakṣiṇīnīḍe) - in a female bird's nest

(noun)

Locative, neuter, singular of pakṣiṇīnīḍa

pakṣiṇīnīḍa - female bird's nest

Compound: pakṣiṇī (female bird) + nīḍa (nest)

Compound type : tatpuruṣa (pakṣiṇī+nīḍa)

• pakṣiṇī – female bird
  noun (feminine)
  Feminine form of pakṣin (bird)
• nīḍa – nest, resting place, abode
  noun (neuter)
  Root: nīḍ (class 1)

क्रीडया (krīḍayā) - playfully (playfully, by sport, with play)

(noun)

Instrumental, feminine, singular of krīḍā

krīḍā - play, sport, amusement

From root krīḍ (to play)

Root: krīḍ (class 1)

न्यवसत् (nyavasat) - he resided (he dwelt, he resided)

(verb)

3rd person , singular, active, past imperfect (laṅ) of nivas

Imperfect

From root vas (to dwell) with upasarga ni

Prefix: ni

Root: vas (class 1)

समाः (samāḥ) - for years (years)

(noun)

Accusative, feminine, plural of samā

samā - year, season