Crosspiece and Two-by-four

Crosspiece noun - A horizontal beam that extends across something.

Two-by-four and crosspiece are semantically related in beam topic. In some cases you can use "Two-by-four" instead a noun "Crosspiece", when it comes to topics like length of material used as support.

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

Crosspiece and two-by-four are semantically related in beam topic. Sometimes you can use "Crosspiece" instead a noun phrase "Two-by-four", if it concerns topics such as length of material used as support.