D defs.my
Entry 2 senses Webster, 1913

Valley

/văl'ē/ · Val·ley · IPA /ˈvæli/
01 n. The space inclosed between ranges of hills or mountains; the strip of land at the bottom of the depressions intersecting a country, includi…
pl. Valleys ((#))
  1. 1.
    The space inclosed between ranges of hills or mountains; the strip of land at the bottom of the depressions intersecting a country, including usually the bed of a stream, with frequently broad alluvial plains on one or both sides of the stream. Also used figuratively.
    “The valley of the shadow of death.” — Ps. xxiii. 4.
    “Sweet interchange Of hill and valley, rivers, woods, and plains.” Milton.
  2. 2.
    The place of meeting of two slopes of a roof, which have their plates running in different directions, and form on the plan a reentrant angle.(Arch.)
Phrases & compounds
Valley board — a board for the reception of the lead gutter in the valley of a roof. The valley board and lead gutter are not usual in the United States.
Valley rafter — the rafter which supports the valley.
Valley roof — a roof having one or more valleys. See Valley, 2, above.