n. 风向标, 风信旗, 变化不定的事物

[机] 轮叶, 叶

Vane \Vane\ (v[=a]n), n. [OE. & E. Prov. E. fane weathercock,
banner, AS. fana a banner, flag; akin to D. vaan, G. fahne,
OHG. fano cloth, gund fano flag, Icel. f[=a]ni, Sw. fana,
Dan. fane, Goth. fana cloth, L. pannus, and perhaps to Gr. ?
a web, ? a bobbin, spool. Cf. {Fanon}, {Pane} a compartment,
panel.]
1. A contrivance attached to some elevated object for the
purpose of showing which way the wind blows; a
weathercock. It is usually a plate or strip of metal, or
slip of wood, often cut into some fanciful form, and
placed upon a perpendicular axis around which it moves
freely.

Aye undiscreet, and changing as a vane. --Chaucer.

2. Any flat, extended surface attached to an axis and moved
by the wind; as, the vane of a windmill; hence, a similar
fixture of any form moved in or by water, air, or other
fluid; as, the vane of a screw propeller, a fan blower, an
anemometer, etc.

3. (Zo["o]l.) The rhachis and web of a feather taken
together.

4. One of the sights of a compass, quadrant, etc.

{Vane of a leveling staff}. (Surv.) Same as {Target}, 3.