humusn.
/ˈhjuːməs/, U.S. /ˈ(h)juməs/ a. Vegetable mould; the dark-brown or black substance resulting from the slow decomposition and oxidization of organic matter on or near the surface of the earth, which, with the products of the decomposition of various rocks, forms the soil in which plants grow.
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the world > the earth > structure of the earth > constituent materials > earth or soil > kind of earth or soil > [noun] > organic soil > humus
humus1796
raw humus1891
mull1923
mor1931
1796 H. Hunter tr. J.-H. B. de Saint-Pierre Stud. Nature (1799) I. 474 That stratum called humus, which..serves as a basis to the vegetable kingdom.
1846 J. Baxter Libr. Pract. Agric. (ed. 4) I. 15 It was usual, formerly, to attribute the carbon or charcoal of plants to their absorption of the humus existing in the ground.
1881 C. Darwin Form. Veg. Mould Introd. 5 Year after year the thrown-up castings cover the dead leaves, the result being a rich humus of great thickness.
b. attributive, as humus acid, humus soil.
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1881 C. Darwin Form. Veg. Mould v. 242 The several humus-acids, which appear..to be generated within the bodies of worms during the digestive process.
1892 Blackwood's Edinb. Mag. July 99 The species of Palaquium require a humus soil.
This entry has not yet been fully updated (first published 1899; most recently modified version published online March 2022).
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