महाभारतः mahābhārataḥ - book-1, chapter-70, verse-25

पितॄन्देवानृषीन्विप्रान्गन्धर्वोरगराक्षसान् ।
नहुषः पालयामास ब्रह्मक्षत्रमथो विशः ॥२५॥

25. pitṝndevānṛṣīnviprāngandharvoragarākṣasān ,
nahuṣaḥ pālayāmāsa brahmakṣatramatho viśaḥ.

25. pitṝn devān ṛṣīn viprān gandharva-uraga-rākṣasān
nahuṣaḥ pālayāmāsa brahma-kṣatram athaḥ viśaḥ

25. Nahusha protected the ancestors, gods, sages, Brahmins, Gandharvas, serpents (Uraga), Rākṣasas, as well as the Brāhmaṇas, Kṣatriyas, and Vaiśyas.

Words meanings summery:

• पितॄन् (pitṝn) - ancestors, forefathers, spirits of the deceased

• देवान् (devān) - gods, deities

• ऋषीन् (ṛṣīn) - sages, seers

• विप्रान् (viprān) - Brahmins, priests

• गन्धर्व-उरग-राक्षसान् (gandharva-uraga-rākṣasān) - Gandharvas, Uragas (serpents), and Rākṣasas (demons)

• नहुषः (nahuṣaḥ) - Nahusha

• पालयामास (pālayāmāsa) - he protected, he guarded

• ब्रह्म-क्षत्रम् (brahma-kṣatram) - the Brāhmaṇa and Kṣatriya classes

• अथः (athaḥ) - as well as (and then, moreover, also)

• विशः (viśaḥ) - the Vaiśya class, common people, settlers

Words meanings and morphology

पितॄन् (pitṝn) - ancestors, forefathers, spirits of the deceased

(noun)

Accusative, masculine, plural of pitṛ

pitṛ - father, ancestor, forefathers (plural)

देवान् (devān) - gods, deities

(noun)

Accusative, masculine, plural of deva

deva - god, deity, divine being

Root: div (class 4)

ऋषीन् (ṛṣīn) - sages, seers

(noun)

Accusative, masculine, plural of ṛṣi

ṛṣi - sage, seer, inspired poet

Root: ṛṣ

विप्रान् (viprān) - Brahmins, priests

(noun)

Accusative, masculine, plural of vipra

vipra - Brahmin, priest, learned person, inspired

From root vip (to tremble, to vibrate), implying inspiration

Root: vip

गन्धर्व-उरग-राक्षसान् (gandharva-uraga-rākṣasān) - Gandharvas, Uragas (serpents), and Rākṣasas (demons)

(noun)

Accusative, masculine, plural of gandharva-uraga-rākṣasa

gandharva-uraga-rākṣasa - Gandharvas, serpents, and demons (as a collective)

Compound type : dvandva (gandharva+uraga+rākṣasa)

• gandharva – celestial musician, demigod
  noun (masculine)
• uraga – serpent, snake (lit. 'moving on the breast')
  noun (masculine)
  Compound of uras (breast) and ga (going)
  Root: gam (class 1)
• rākṣasa – demon, evil spirit
  noun (masculine)
  Root: rakṣ (class 1)

Note: This is an accusative plural form of a compound listing multiple classes of beings.

नहुषः (nahuṣaḥ) - Nahusha

(proper noun)

Nominative, masculine, singular of nahuṣa

nahuṣa - Name of an ancient king, son of Ayu

पालयामास (pālayāmāsa) - he protected, he guarded

(verb)

3rd person , singular, active, perfect (periphrastic) (lit) of pāl

Periphrastic Perfect, formed by root pāl + ām + perfect of as (to be)

Root: pāl (class 10)

ब्रह्म-क्षत्रम् (brahma-kṣatram) - the Brāhmaṇa and Kṣatriya classes

(noun)

Accusative, neuter, singular of brahma-kṣatra

brahma-kṣatra - The Brāhmaṇa and Kṣatriya castes/classes (collectively)

Compound type : dvandva (brahman+kṣatra)

• brahman – Brāhmaṇa (member of the priestly class), sacred text, the ultimate reality (Brahman)
  noun (neuter)
  Root: bṛh (class 1)
• kṣatra – Kṣatriya (member of the warrior/ruling class), rule, dominion
  noun (neuter)
  Root: kṣi (class 5)

Note: Grammatically singular, but semantically refers to plural classes.

अथः (athaḥ) - as well as (and then, moreover, also)

(indeclinable)

Note: Visarga sandhi from athaḥ to atho before a soft consonant or vowel.

विशः (viśaḥ) - the Vaiśya class, common people, settlers

(noun)

Accusative, feminine, plural of viś

viś - people, community, clan, Vaiśya (member of the merchant/farmer class)

From root viś (to enter, to settle)

Root: viś (class 6)

Note: Also nominative singular. Context indicates accusative plural.