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subsoil

[suhb-soil] / ˈsʌbˌsɔɪl /
NOUN
earth
Synonyms
STRONGEST
clay coast dirt dust gravel land mud sand shore surface terrain turf
STRONG
alluvium clod compost deposit fill glebe humus loam marl mold muck sod topsoil
WEAK
dry land peat moss terra firma terrane
Antonyms
STRONGEST
sky

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.