योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-43, verse-41

एकाभावे द्वयोः शान्तिः पवनस्पन्दयोरिव ।
नूनमेकोपशान्त्यैव निःसारे परमार्थतः ॥ ४१ ॥

ekābhāve dvayoḥ śāntiḥ pavanaspandayoriva ,
nūnamekopaśāntyaiva niḥsāre paramārthataḥ 41

41. eka-abhāve dvayoḥ śāntiḥ pavana-spanday-oḥ iva |
nūnam eka-upaśāntyā eva niḥsāre paramārthataḥ ||

41. eka-abhāve pavana-spanday-oḥ iva dvayoḥ śāntiḥ (bhavati)
nūnam eka-upaśāntyā eva niḥsāre paramārthataḥ (nāśyati)

41. When one of them is absent, both find peace, just like wind and its vibration. Certainly, by the cessation of one alone, what is truly insubstantial vanishes.

Words meanings summery:

• एक-अभावे (eka-abhāve) - in the absence of one, when one is non-existent

• द्वयोः (dvayoḥ) - of both, for both

• शान्तिः (śāntiḥ) - peace, tranquility, cessation

• पवन-स्पन्दय्-ओः (pavana-spanday-oḥ) - of wind and vibration

• इव (iva) - like, as, as if

• नूनम् (nūnam) - certainly, surely, indeed

• एक-उपशान्त्या (eka-upaśāntyā) - by the cessation of one alone

• एव (eva) - alone, only, indeed

• निःसारे (niḥsāre) - in what is insubstantial, for what is futile

• परमार्थतः (paramārthataḥ) - truly, ultimately, in the highest sense

Words meanings and morphology

एक-अभावे (eka-abhāve) - in the absence of one, when one is non-existent

(noun)

Locative, masculine, singular of ekābhāva

ekābhāva - absence of one

Compound type : tatpuruṣa (eka+abhāva)

• eka – one, single
  adjective (masculine)
• abhāva – non-existence, absence, non-being
  noun (masculine)

द्वयोः (dvayoḥ) - of both, for both

(adjective)

Genitive, masculine, dual of dvi

dvi - two, both

शान्तिः (śāntiḥ) - peace, tranquility, cessation

(noun)

Nominative, feminine, singular of śānti

śānti - peace, tranquility, cessation

पवन-स्पन्दय्-ओः (pavana-spanday-oḥ) - of wind and vibration

(noun)

Genitive, masculine, dual of pavanaspanda

pavanaspanda - wind and vibration

Compound type : dvandva (pavana+spanda)

• pavana – wind, air
  noun (masculine)
• spanda – vibration, tremor, movement
  noun (masculine)

इव (iva) - like, as, as if

(indeclinable)

नूनम् (nūnam) - certainly, surely, indeed

(indeclinable)

एक-उपशान्त्या (eka-upaśāntyā) - by the cessation of one alone

(noun)

Instrumental, feminine, singular of ekopaśānti

ekopaśānti - cessation of one

Compound type : tatpuruṣa (eka+upaśānti)

• eka – one, single
  adjective (masculine)
• upaśānti – cessation, tranquility, subsidence
  noun (feminine)

एव (eva) - alone, only, indeed

(indeclinable)

निःसारे (niḥsāre) - in what is insubstantial, for what is futile

(adjective)

Locative, neuter, singular of niḥsāra

niḥsāra - insubstantial, fruitless, worthless, unsubstantiality

Note: Used substantively, meaning 'in the insubstantial (reality)' or 'with respect to the insubstantial'.

परमार्थतः (paramārthataḥ) - truly, ultimately, in the highest sense

(indeclinable)

Derived from 'paramārtha' with the suffix -tas.