What are the etymologies and literal meanings of the words (kṣatriya, śūdra, etc.) used to indicate one's varṇa?

Question

For brāhmaṇa, there is already a question here: What is the etymology of brahman/brahmin?

For śūdra, Monier Williams says "of doubtful derivation". Apte says:

शूद्रः [शुच्-रक् पृषो˚ चस्य दः दीर्घः Uṇ. 2.19]

I'm not sure what that means though.

What are the literal meanings and derivations of kṣatriya and vaiśya?

Answer 1

I can answer for kshatriya and shudra.

Kshatriya, according to wikipedia, comes from kṣatra, which means "rule, authority," because Kshatriyas are law enforcement and military.

The word "shudra" etymologically means one who grieves or sorrows.

In the Chandogya Upanishad there is a story where a king is addressed by the word "shudra" because he is in grief that he has not acquired the knowledge of Brahman yet.

Brahma Sutra 1.3.33 explains the usage of the word "shudra" in that context to mean "one who grieves."

Here is Ramanujacharya's commentary on that sutra:

From what the text says about Jânasruti Pautrâyana having been taunted by a flamingo for his want of knowledge of Brahman, and having thereupon resorted to Raikva, who possessed the knowledge of Brahman, it appears that sorrow (such) had taken possession of him; and it is with a view to this that Raikva addresses him as Sûdra. For the word Sûdra, etymologically considered, means one who grieves or sorrows (sochati). The appellation 'sûdra' therefore refers to his sorrow, not to his being a member of the fourth caste.

Shankaracharya says the same thing in his commentary on that sutra:

The word 'Sûdra' can moreover be made to agree with the context in which it occurs in the following manner. When Jânasruti Pautrâyana heard himself spoken of with disrespect by the flamingo ('How can you speak of him, being what he is, as if he were like Raikva with the car?' IV, i, 3), grief (such) arose in his mind, and to that grief the rishi Raikva alludes with the word Sûdra, in order to show thereby his knowledge of what is remote.

Now there is another etymology given by SAR Prasanna Venkatachariar Chaturvedi Swami which means "one who removes the grief of another through his service," because Shudras' duty is to serve.