From The Collaborative International Dictionary of English v.0.48:
Spile \Spile\ (sp[imac]l), n. [Cf. LG. spile, dial. G. speil,
speiler, D. spijl. [root]170.]
1. A small plug or wooden pin, used to stop a vent, as in a
cask.
[1913 Webster]
2. A small tube or spout inserted in a tree for conducting
sap, as from a sugar maple.
[1913 Webster]
3. A large stake driven into the ground as a support for some
superstructure; a pile.
[1913 Webster]
4. (Mining) One of the thick laths or poles driven
horizontally ahead on top of a set of the main timbering
in advancing a level in loose ground.
Syn: forepole; spill[2d].
[RDH]
Spile hole, a small air hole in a cask; a vent.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Spile \Spile\ (sp[imac]l), v. t.
To supply with a spile or a spigot; to make a small vent in,
as a cask.
[1913 Webster]