What is "eaves board"

Eaves \Eaves\, n. pl. [OE. evese, pl. eveses, AS. efese eaves, brim, brink; akin to OHG. obisa, opasa, porch, hall, MHG. obse eaves, Icel. ups, Goth. ubizwa porch; cf. Icel. upsar-dropi, OSw. ops["a]-drup water dropping from the eaves. Probably from the root of E. over. The s of eaves is in English regarded as a plural ending, though not so in Saxon. See Over, and cf. Eavesdrop.]

1. (Arch.) The edges or lower borders of the roof of a building, which overhang the walls, and cast off the water that falls on the roof.

2. Brow; ridge. [Obs.] ``Eaves of the hill.''
   --Wyclif.

3. Eyelids or eyelashes. And closing eaves of wearied eyes. --Tennyson. Eaves board (Arch.), an arris fillet, or a thick board with a feather edge, nailed across the rafters at the eaves of a building, to raise the lower course of slates a little, or to receive the lowest course of tiles; -- called also eaves catch and eaves lath. Eaves channel, Eaves gutter, Eaves trough. Same as Gutter, 1. Eaves molding (Arch.), a molding immediately below the eaves, acting as a cornice or part of a cornice. Eaves swallow (Zo["o]l.).

   1. The cliff swallow; -- so called from its habit of building retort-shaped nests of mud under the eaves of buildings. See Cliff swallow, under Cliff.

   2. The European swallow.