yelm (yelm) n. v. —n. a bundle of reaped grain, often as to be used for thatching; haulm. —v. select and lay out grain for thatching. [OE yelm, yielm, yilm]

yel·mer (yel´mər) n. one who lays out yelms.

yer·ba san·ta (yėr´bə sän´tə) n. 1 any of several low shrubs of the genus Eriodictyon Benth. (especially E. glutinosum Benth., all of the Hydrophyllaceae), native to California and surrounding areas, bearing alternate aromatic coriaceous leaves, and treating bronchial and pulmonary complaints. 2 hoja santa. [< Sp. hierba herb, plant + santa holy]

yield (yēld) v.t. n. —v.t. 1 of an individual or a community: a bear or generate fruit. b give forth of its own substance. 2 of an individual, put forth a bud of some nature. —n. the crop or amount of a product obtained from a chemical, harvesting, or growth process. [< OE yeild, yalld, ʒeld]

y·lang-y·lang´läng´ ē´läng´) n. 1 a small tree (Cananga odorata (Lam.) Hook.f. & Thomson, of the Annonaceae), native to Malaysia and the Philippines, and bearing deeply-fragrant yellow flowers. 2 a sweet-scented oil extracted from the flowers of this tree, and used in perfumery, and also in aromatherapy; macassar oil. [< Tagalog ilang-ilang]

yun·gas (yün´gəs) a complex mosaic of forest habitats found in the eastern foothills of the Andes mountain chain in Bolivia, Peru, and Argentina, and characterised by warmth, moist climate, and varied substrates and altitudes. A history of use for small-scale agriculture also persists in this region. [< Sp. yungas < Quetchua yunka]