Bombshell and Two-by-four

Bombshell noun - Something that makes a strong impression because it is so unexpected.

Two-by-four and bombshell are semantically related. In some cases you can use "Two-by-four" instead a noun "Bombshell".

Two-by-four noun - A timber measuring (slightly under) 2 inches by 4 inches in cross section.

Bombshell and two-by-four are semantically related. Sometimes you can use "Bombshell" instead a noun phrase "Two-by-four".