Cusp and Shim

Cusp noun - An interval of time just before the onset of something.

Shim and cusp are semantically related In some cases you can use "Shim" instead a noun "Cusp".

Shim noun - A thin wedge of material (wood or metal or stone) for driving into crevices.

Cusp and shim are semantically related in solid piece topic. Sometimes you can use "Cusp" instead a noun "Shim".