from
The Collaborative International Dictionary of English v.0.48
Gib \Gib\, n. [Etymol. uncertain.]
A piece or slip of metal or wood, notched or otherwise, in a
machine or structure, to hold other parts in place or bind
them together, or to afford a bearing surface; -- usually
held or adjusted by means of a wedge, key, or screw.
[1913 Webster]
{Gib and key}, or {Gib and cotter} (Steam Engine), the fixed
wedge or gib, and the driving wedge,key, or cotter, used
for tightening the strap which holds the brasses at the
end of a connecting rod.
[1913 Webster]