In western Canada this refers to any piece of lumber. It doesn’t have to be strictly two inches by four inches (Canada does use the imperial system in construction).
“We’re gonna build a treehouse. We just need some two-by-fours and a hammer and some nails.”
Definition: Two 4x4 posts bolted/screwed/glued together, to make a single approximately 4x8 board. Invented by a Canadian contractor working on a very overbuilt deck.
This section is supported by CanadianTwo by Fours, so it's not going anywhere.
A particularly fat, disgusting person in reference to the schoolyard rhyme of the same name:
Fatty Fatty Two by Four
Can't get through the bathroom door So he did it on the floor
Licked it up and asked for more
Did you see that fatty fatty two by four at KFC ordering a whole family bucket of chicken for himself?
When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).