योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-54, verse-17

ततस्तृतीयावसरे प्रणवस्योपशान्तिदे ।
पूरणप्रपूरको नाम प्राणानामभवत्क्रमः ॥ १७ ॥

tatastṛtīyāvasare praṇavasyopaśāntide ,
pūraṇaprapūrako nāma prāṇānāmabhavatkramaḥ 17

17. tataḥ tṛtīyāvasare praṇavasya upaśāntide
pūraṇaprapūrakaḥ nāma prāṇānām abhavat kramaḥ

17. tataḥ tṛtīyāvasare praṇavasya upaśāntide
prāṇānām pūraṇaprapūrakaḥ nāma kramaḥ abhavat

17. Then, at the third stage, which bestows tranquility upon Om (praṇava), a particular process related to the vital breaths (prāṇa), named Pūraṇaprapūraka, came into existence.

Words meanings summery:

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

• तृतीयावसरे (tṛtīyāvasare) - at the third stage (on the third occasion, at the third stage)

• प्रणवस्य (praṇavasya) - of Om (praṇava) (of Om, of the sacred syllable Om)

• उपशान्तिदे (upaśāntide) - which bestows tranquility (granting peace, bestowing quietude)

• पूरणप्रपूरकः (pūraṇaprapūrakaḥ) - the process named Pūraṇaprapūraka (complete filling and refilling) (filling and refilling, a specific breath technique)

• नाम (nāma) - named (indicating it is a proper name/designation) (by name, indeed, namely)

• प्राणानाम् (prāṇānām) - of the vital breaths (prāṇa) (of the vital airs, of the breaths, of life forces)

• अभवत् (abhavat) - came into existence, occurred (became, occurred, was)

• क्रमः (kramaḥ) - a process, a stage (sequence, order, process, stage)

Words meanings and morphology

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

(indeclinable)

तृतीयावसरे (tṛtīyāvasare) - at the third stage (on the third occasion, at the third stage)

(noun)

Locative, masculine, singular of tṛtīyāvasara

tṛtīyāvasara - third occasion, third stage

Compound type : tatpuruṣa (tṛtīya+avasara)

• tṛtīya – third
  adjective (feminine)
• avasara – occasion, opportunity, stage, time
  noun (masculine)
  Prefix: ava
  Root: sṛ (class 1)

प्रणवस्य (praṇavasya) - of Om (praṇava) (of Om, of the sacred syllable Om)

(noun)

Genitive, masculine, singular of praṇava

praṇava - the sacred syllable Om, a mystic or sacred syllable

Prefix: pra

Root: nu (class 2)

उपशान्तिदे (upaśāntide) - which bestows tranquility (granting peace, bestowing quietude)

(adjective)

Locative, masculine, singular of upaśāntida

upaśāntida - granting peace, giving tranquility

Derived from upaśānti (peace) + da (giver, from root dā 'to give').

Compound type : tatpuruṣa (upaśānti+da)

• upaśānti – peace, tranquility, quietude
  noun (feminine)
  Prefix: upa
  Root: śam (class 4)
• da – giver, bestower
  adjective (masculine)
  Suffix -da, derived from the root dā (to give)
  Root: dā (class 3)

Note: Agrees with tṛtīyāvasare.

पूरणप्रपूरकः (pūraṇaprapūrakaḥ) - the process named Pūraṇaprapūraka (complete filling and refilling) (filling and refilling, a specific breath technique)

(noun)

Nominative, masculine, singular of pūraṇaprapūraka

pūraṇaprapūraka - filling and refilling, a type of prāṇāyāma involving complete inhalation and exhalation or retention

Compound type : karmadhāraya (pūraṇa+prapūraka)

• pūraṇa – filling, completing, inhalation
  noun (neuter)
  action noun
  Derived from root pṛ 'to fill'
  Root: pṛ (class 9)
• prapūraka – completely filling, intense filling, an agent of filling
  noun (masculine)
  agent noun
  Derived from root pṛ 'to fill' with pra- prefix
  Prefix: pra
  Root: pṛ (class 9)

नाम (nāma) - named (indicating it is a proper name/designation) (by name, indeed, namely)

(indeclinable)

प्राणानाम् (prāṇānām) - of the vital breaths (prāṇa) (of the vital airs, of the breaths, of life forces)

(noun)

Genitive, masculine, plural of prāṇa

prāṇa - vital air, breath, life-force, energy

Prefix: pra

Root: an (class 2)

अभवत् (abhavat) - came into existence, occurred (became, occurred, was)

(verb)

3rd person , singular, active, imperfect (laṅ) of bhū

Root: bhū (class 1)

क्रमः (kramaḥ) - a process, a stage (sequence, order, process, stage)

(noun)

Nominative, masculine, singular of krama

krama - step, sequence, order, method, stage, process

Root: kram (class 1)

Note: Subject of abhavat.