Today, we use the phrase ‘square meal’ to refer to a full, balanced meal. We might say, “Boy, I’m full. That was a square meal” or “I’m hungry, let’s find a place we can get a square meal.” It basically means a good and filling meal. One good meal is called a square meal but we also have the phrase, three square meals. This phrase is so common that a recent translation of the Bible changed “Give us this day our daily bread” to “Keep us alive with three square meals.” Less than poetic, for sure.
Most origin stories of the phrase claim it came from British and American naval ships of the 1700 or 1800’s. There are two versions of this story. The most common claims that sailors aboard ship had their meals served to them on square wooden trays or plates, that they either carried back to their bunks, where the plates could be stored easily, or that were stored elsewhere. Since they only used these squares when they were getting a full meal, probably dinner, the phrase ‘a square meal’ came to be associated with a full and satisfying dinner.
Another variation on the naval story has it that plates would be set on wooden squares upon the galley table to keep them from sliding off, and that at some point the squares were permanently nailed down.
A similar story left out the naval connection, and simply claims that British people used to eat off of wooden squares with the middles hollowed out into a depression for gravy, and perhaps another for salt. This supposedly dates back to medieval times where these wooden platters were called trenchers or simply boards. Travelers would carry around these squares to use any time they got a full meal, resulting in the same association as the naval stories, above.
Others, instead of attributing the phrase to naval ships, replace navy sailors with pirates. Here the idea is exactly the same: Pirates used to eat their meals off of wooden platters. This has also been claimed to be the origin of the phrase fair and square, since each pirate would receive his fair share of the sustenance. Or, sometimes only the hardest workers would get a square meal meaning that when all received a full meal, they were getting a fair and square meal. Since the pirates were supposed to have turned their plates over to eat dessert on the other side, this is said to be the origin of clean your plate before you have dessert.
It is quite likely that both naval and pirate ships used similar plates, as wood makes sense aboard a ship, being unbreakable (although pewter may have replaced wood at some point), and the square shape can be more efficiently stored away. There are many primitive examples of these wooden plates or trenchers, some of which are oblong but squarish bowls, being more shallow or deeper, others of which are flat squares of wood with a rounder depression turned into the middle and another smaller hole in the corner, supposedly for salt. These may have been made with beech, sycamore, or maple. Before perhaps 1500, these “trenchers” would have been made of large pieces of stale bread.
One explanation, which is more of a theory than any serious investigation into the etymology of the phrase, supposed that the phrase came about because of the association of square with right, since a square’s angles are right angles. However, the word square is definitely associated with things that are right and proper. Not only fair and square from above but to square away, which means to “take care of things and make them right,” and square deal which is a fair and proper deal. Also, to be square with someone is to be even with him and to square up is to pay a debt.