two-by-four

[ too-bahy-fawr, -fohr, -buh- ]

/ ˈtu baɪˌfɔr, -ˌfoʊr, -bə- /

two units thick and four units wide, especially in inches.

Informal. lacking adequate space; cramped: a small, two-by-four room.

Informal. unimportant; insignificant: Theirs was a petty, two-by-four operation.

a timber measuring 2 by 4 inches (5 × 10 cm) in cross section, when untrimmed: equivalent to 1 5/8 by 3 5/8 inches (4.5 × 9 cm) when trimmed.

Origin of two-by-four

An Americanism dating back to 1880–85

What about the law against the IRS smacking Tea Party-type nonprofits over the head with a two-by-four?

PJ’s Political Forecast: Cloudy with a Chance of Meatheads |P. J. O’Rourke |March 14, 2014 |DAILY BEAST
This platform should be fastened to the first, with the end which has not been battened secured to the two-by-four at C.

The Boy Craftsman |A. Neely Hall
There wasn't much money on board these two-by-four boats, anyhow, so he wasn't losing much.

Parrot & Co. |Harold MacGrath
And time after time Stud brought the two-by-four crashing down between the maddened animal's eyes.

Plowing On Sunday |Sterling North

Zircon had found a piece of two-by-four lumber about eight feet long, and he was swinging it like a flail.

The Caves of Fear |John Blaine
Using the two-by-four as a fulcrum, he began levering the door upward and outward.

The Boy Scouts of Lakeville High |Leslie W. Quirk

two-by-four

a length of untrimmed timber with a cross section that measures 2 inches by 4 inches

a trimmed timber joist with a cross section that measures 1 1/2 inches by 3 1/2 inches