योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-14, verse-77

अविकल्पतदात्मत्वात्सत्तासत्तैकतैव च ।
अवयवावयविता शब्दार्थौ शशशृङ्गवत् ॥ ७७ ॥

avikalpatadātmatvātsattāsattaikataiva ca ,
avayavāvayavitā śabdārthau śaśaśṛṅgavat 77

77. avikalpatadātmatvāt sattāsattāikatā eva ca
avayavāvayavitā śabdārthau śaśaśṛṅgavat

77. avikalpatadātmatvāt sattāsattāikatā ca
avayavāvayavitā śabdārthau eva śaśaśṛṅgavat

77. Due to the non-conceptual (avikalpa) nature of that ultimate reality (ātman), the oneness of existence and non-existence, as well as the relation of part and whole, and word and meaning—all these are like a rabbit's horn (i.e., illusory).

Words meanings summery:

• अविकल्पतदात्मत्वात् (avikalpatadātmatvāt) - due to the ultimate reality being non-conceptual and its true essence (ātman) (due to the nature of being non-conceptual and that ultimate self)

• सत्तासत्ताइकता (sattāsattāikatā) - the oneness of existence and non-existence

• एव (eva) - indeed, only, just

• च (ca) - and

• अवयवावयविता (avayavāvayavitā) - the relation of part and whole

• शब्दार्थौ (śabdārthau) - word and meaning (dual)

• शशशृङ्गवत् (śaśaśṛṅgavat) - like a rabbit's horn (i.e., non-existent, illusory)

Words meanings and morphology

अविकल्पतदात्मत्वात् (avikalpatadātmatvāt) - due to the ultimate reality being non-conceptual and its true essence (ātman) (due to the nature of being non-conceptual and that ultimate self)

(noun)

Ablative, neuter, singular of avikalpatadātmatva

avikalpatadātmatva - the state or nature of being non-conceptual and one with that (ultimate reality)

Compound noun formed from 'a-vikalpa' (non-conceptual), 'tat-ātman' (that self/essence), and '-tva' (abstract noun suffix). Ablative case ending '-āt'.

Compound type : tatpurusha (a+vikalpa+tat+ātman+tva)

• a – not, non-, un-
  indeclinable
• vikalpa – difference, distinction, mental construction, conceptualization, option
  noun (masculine)
  From 'vi' + root 'kḷp' (to arrange, form)
  Prefix: vi
  Root: kḷp (class 1)
• tat – that, it
  pronoun (neuter)
• ātman – self, soul, essence, spirit, the Supreme Spirit
  noun (masculine)
  Root: an (class 2)
• tva – state, condition, -ness, -hood
  suffix (neuter)
  Abstract noun suffix, forms neuter nouns from adjectives or nouns.

सत्तासत्ताइकता (sattāsattāikatā) - the oneness of existence and non-existence

(noun)

Nominative, feminine, singular of sattāsattāikatā

sattāsattāikatā - the unity of being and non-being, the oneness of reality and unreality

Compound of 'sattā' (existence), 'asattā' (non-existence), and 'ekatā' (oneness)

Compound type : tatpurusha (sattā+asattā+ekatā)

• sattā – existence, being, reality
  noun (feminine)
  From root 'as' (to be) + suffix '-tā'
  Root: as (class 2)
• asattā – non-existence, unreality
  noun (feminine)
  Negation of 'sattā' with prefix 'a-'
  Prefix: a
  Root: as (class 2)
• ekatā – oneness, unity, identity
  noun (feminine)
  From 'eka' (one) + suffix '-tā'

एव (eva) - indeed, only, just

(indeclinable)

च (ca) - and

(indeclinable)

अवयवावयविता (avayavāvayavitā) - the relation of part and whole

(noun)

Nominative, feminine, singular of avayavāvayavitā

avayavāvayavitā - the state of being a part and a whole; the relationship between part and whole

Compound of 'avayava' (part) and 'avayavitā' (wholeness, state of having parts)

Compound type : tatpurusha (avayava+avayavitā)

• avayava – part, member, limb
  noun (masculine)
  From 'ava' + root 'yu' (to join, mix)
  Prefix: ava
  Root: yu (class 2)
• avayavitā – the state of having parts, wholeness
  noun (feminine)
  From 'avayavin' (having parts, whole) + suffix '-tā'

शब्दार्थौ (śabdārthau) - word and meaning (dual)

(noun)

Nominative, masculine, dual of śabdārtha

śabdārtha - word and its meaning

Dvandva compound of 'śabda' (word) and 'artha' (meaning)

Compound type : dvandva (śabda+artha)

• śabda – sound, word, speech, language
  noun (masculine)
• artha – meaning, sense, purpose, object, wealth
  noun (masculine)

शशशृङ्गवत् (śaśaśṛṅgavat) - like a rabbit's horn (i.e., non-existent, illusory)

(adjective)

of śaśaśṛṅgavat

śaśaśṛṅgavat - like a rabbit's horn (a classic example of an impossible or non-existent thing)

Compound of 'śaśa' (rabbit) and 'śṛṅga' (horn) with the possessive/similative suffix '-vat'

Compound type : tatpurusha (śaśa+śṛṅga+vat)

• śaśa – rabbit, hare
  noun (masculine)
• śṛṅga – horn, peak, summit
  noun (neuter)
• vat – like, similar to, possessed of
  suffix
  Taddhita suffix forming adjectives or adverbs of comparison or possession.

Note: Functions as an adverb here, modifying the implied verb 'are'.