D defs.my
Entry 1 sense Webster, 1913

Spillway

/spĭl'-wāˌ/ · Spill·way · IPA /spˈɪlwˌeɪ/
01 n. A sluiceway or passage for superfluous water in a reservoir, to prevent too great pressure on the dam.
  1. 1.
    A sluiceway or passage for superfluous water in a reservoir, to prevent too great pressure on the dam.