Definition of colluvium in US English:

colluvium

noun

Geology
  • Material which accumulates at the foot of a steep slope.

    • ‘Bronze Age and Neolithic pottery and flints from the basal soil and the colluvium indicate that a settlement was nearby.’
    • ‘Archaeologists can use the evidence of pollen, alluvium (flood-deposits), and colluvium (hill-wash) to study the past environment.’
    • ‘In the southern part of the valley, the Serghaya Fault Zone follows the mountain front juxtaposing recent alluvium and colluvium against late Quaternary lake sediments, Neogene conglomerates, and Cretaceous carbonates.’
    • ‘Deposits formed on hill slopes are called colluvium where they are fine-grained, and taluvium if they are of coarse-grained rock debris.’
    • ‘Soils of the gap floor are Andover, a deep, poorly drained loam of low permeability derived from sandstone and shale colluvium.’

Origin

Early 20th century: from Latin colluvies ‘confluence of matter’, from colluere ‘to rinse’, from col- ‘together’ + luere ‘to wash’.

Pronunciation

colluvium

/kəˈlo͞ovēəm/