योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-146, verse-4

गिरिवृष्टिर्झटित्येव कुतोऽपि समुपाययौ ।
उह्यमानवनाभोगशिखरग्रामपत्तना ॥ ४ ॥

girivṛṣṭirjhaṭityeva kuto'pi samupāyayau ,
uhyamānavanābhogaśikharagrāmapattanā 4

4. girivṛṣṭiḥ jhaṭiti eva kutaḥ api samupāyayau
uhyamānavanābhogaśikharagrāmapattanā

4. kutaḥ api girivṛṣṭiḥ jhaṭiti eva samupāyayau
uhyamānavanābhogaśikharagrāmapattanā

4. Suddenly, from somewhere, a shower of mountains (girivṛṣṭi) emerged, carrying away extensive forests, peaks, villages, and towns.

Words meanings summery:

• गिरिवृष्टिः (girivṛṣṭiḥ) - a cataclysmic flood or deluge carrying landmasses (shower of mountains, deluge of debris)

• झटिति (jhaṭiti) - suddenly, instantly, quickly

• एव (eva) - indeed, only, just, certainly

• कुतः (kutaḥ) - from where, whence

• अपि (api) - "some" (from somewhere) (also, even, perhaps, (with interrogative) some)

• समुपाययौ (samupāyayau) - came forth, appeared, approached

• उह्यमानवनाभोगशिखरग्रामपत्तना (uhyamānavanābhogaśikharagrāmapattanā) - (the shower of mountains) which was carrying away vast areas of forests, peaks, villages, and towns (bearing away expansive forests, peaks, villages, and towns)

Words meanings and morphology

गिरिवृष्टिः (girivṛṣṭiḥ) - a cataclysmic flood or deluge carrying landmasses (shower of mountains, deluge of debris)

(noun)

Nominative, feminine, singular of girivṛṣṭi

girivṛṣṭi - shower of mountains, rain of mountains, deluge of debris

Compound type : tatpurusha (giri+vṛṣṭi)

• giri – mountain, hill
  noun (masculine)
  Root: gṝ (class 6)
• vṛṣṭi – rain, shower, downpour
  noun (feminine)
  from root vṛṣ (to rain)
  Root: vṛṣ (class 1)

झटिति (jhaṭiti) - suddenly, instantly, quickly

(indeclinable)

एव (eva) - indeed, only, just, certainly

(indeclinable)

कुतः (kutaḥ) - from where, whence

(indeclinable)

adverbial suffix -tas

Root: kim

अपि (api) - "some" (from somewhere) (also, even, perhaps, (with interrogative) some)

(indeclinable)

समुपाययौ (samupāyayau) - came forth, appeared, approached

(verb)

3rd person , singular, active, perfect (Lit) of i

perfect tense

3rd person singular perfect tense form of root i (to go) with prefixes sam and upa.

Prefixes: sam+upa

Root: i (class 2)

उह्यमानवनाभोगशिखरग्रामपत्तना (uhyamānavanābhogaśikharagrāmapattanā) - (the shower of mountains) which was carrying away vast areas of forests, peaks, villages, and towns (bearing away expansive forests, peaks, villages, and towns)

(adjective)

Nominative, feminine, singular of uhyamānavanābhogaśikharagrāmapattana

uhyamānavanābhogaśikharagrāmapattana - bearing away extensive forests, peaks, villages, and towns

Compound type : tatpurusha (uhyamāna+vana+ābhoga+śikhara+grāma+pattana)

• uhyamāna – being carried, being borne
  participle (masculine/feminine/neuter)
  present passive participle
  from root vah (to carry) in passive voice, with ŚānaC suffix.
  Root: vah (class 1)
• vana – forest, wood
  noun (neuter)
• ābhoga – expanse, extent, circumference, full enjoyment
  noun (masculine)
  from root bhuj (to enjoy/bend) with prefix ā
  Prefix: ā
  Root: bhuj (class 7)
• śikhara – peak, summit, crest
  noun (neuter)
• grāma – village, community
  noun (masculine)
• pattana – town, city
  noun (neuter)
  Root: pat (class 1)

Note: This is an adjective in feminine singular nominative case, agreeing with girivṛṣṭiḥ.