Alluvial

adjective (also, rarely, noun in mining contexts: alluvial ground or deposits worked for minerals)

/əˈluːviəl/

Relating to or composed of sediment (clay, silt, sand, gravel) deposited by flowing water, especially in river valleys and floodplains.

✍️ Usage in a UPSC answer

The alluvial plains of the Indo-Gangetic belt, replenished annually by silt-laden rivers, sustain nearly half of India's population, making their protection from unregulated sand mining and urban encroachment a first-order imperative of environmental governance.

Synonyms

fluvialsedimentarysilt-depositeddepositionalriverinedeltaic

Antonyms

residual (of soils formed in situ)aeolian (wind-deposited)glacialcolluvial

🌱 Word Family

alluvium (n), alluvion (n), alluvial (adj), alluvials (n pl), alluviate (v, rare)

🔡 Root

Latin ad- = to/against + lavere = to wash → alluere = to wash against → Medieval Latin alluvius

📜 Etymology

From Medieval Latin alluvius ("washed against"), derived from Latin alluere ("to wash against"), combining ad ("to, against") and lavere ("to wash"); first attested in English in 1771.

🧠 Memory Hook

Root hook: ad- ('onto') + luere ('to wash' — same root as dilute and lavatory): alluvial soil is what the river WASHES ONTO the land. Picture the Ganga washing ALL its silt onto the plain.

📝 Seen in UPSC Question Papers

Prelims 2018 — Soils
Prelims 2015 — Soils
Prelims 2013 — Soils

Real UPSC previous-year questions whose text uses “Alluvial” — proof this word earns its place on your list.

🌍 Geography 📖 Seen in: Indian Physical Geography

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