Affluent Definition

ăflo͝o-ənt, ə-flo͝o-

adjective

Generously supplied with money, property, or possessions; prosperous or rich.

American Heritage

Flowing freely.

Webster's New World

Manifesting or requiring wealth.

Affluent homes; affluent living.

American Heritage

Plentiful; abundant.

Webster's New World

Flowing freely; copious.

American Heritage

Synonyms:

Antonyms:

noun

A stream or river that flows into a larger one; a tributary.

American Heritage

A tributary stream.

Webster's New World

A person who is well-off financially.

American Heritage

An affluent person.

Webster's New World

Wealthy people considered as a group. Often used with the.

American Heritage

Synonyms:

Antonyms:

Other Word Forms of Affluent

Singular:

affluent

Plural:

affluents

Middle French affluent, from Latin affluentem, accusative singular of affluēns, present active participle of affluō (“flow to or towards; overflow with”), from ad (“to, towards”) + fluō (“flow”) (cognate via latter to fluid, flow). Sense of “wealthy” (plentiful flow of goods) c. 1600, which also lead to nominalization affluence.

From Wiktionary
Middle English abundant, flowing from Old French from Latin affluēns affluent- present participle of affluere to abound in ad- ad- fluere to flow bhleu- in Indo-European roots

From American Heritage Dictionary of the English Language, 5th Edition
Only relation to antonym indigent is common Latinate suffix +‎ -ent.

From Wiktionary