fishplate

[fish-pleyt] /ˈfɪʃˌpleɪt/
noun
1.
a metal or wooden plate or slab, bolted to each of two members that have been butted or lapped together.
2.
Railroads Now Rare. a joint bar.
Origin
1850-55; fish, alteration of French fiche fastening, derivative of ficher to fasten, fix (see fichu) + plate1
British Dictionary definitions for fishplate

fishplate

/ˈfɪʃˌpleɪt/
noun
1.
a flat piece of metal joining one rail, stanchion, or beam to another