Dear Word Detective: I grew up on a farm in central Illinois. We always referred to the upper part of the barn as the “hay mow.” A great place to play! My friend who grew up on a Missouri farm didn’t know what I was talking about. She said they simply called it the “hay loft.” So what does “mow” mean? It’s not pronounced like “moe,” but like “cow.” — Susan.
Interesting question. It took me a while after moving from New York City to rural Ohio to learn the difference between hay (various kinds of grass, etc., used primarily as food for livestock) and straw (dried stalks of threshed grain, used primarily for livestock bedding). A few years ago, our neighbor, who has about three acres of front lawn (as do we), got sick of having to mow it every week (as do I). Now he just mows around the edges and grows hay in the middle, which he sells to a local farmer. I’d love to do the same, but we have too many trees. Perhaps we should sell both hay and firewood.
The key to the mystery of “hay-mow” (and the reason that the “mow” in “hay-mow” rhymes with “cow”) is that there are actually two separate “mows” in English. (Truth be told, there are eleven “mows,” six nouns and five verbs, but we’re only going to examine the two most common forms.)
When we “mow” (rhymes with “moe”) the lawn, we’re using the verb “to mow,” meaning “to cut down grass or grain with a scythe or machine.” This “mow” is very old word, going back to Indo-European roots with the sense of “to cut.” The transferred sense of “mow” meaning “to cut down in battle; to destroy or kill indiscriminately or in great numbers” appeared in the 16th century. The use of “mow down” to mean “strike with an automobile” is first attested in print in the 1960s, but it’s probably much older.
The “mow” in “hay-mow” (rhymes with “cow”) is a completely unrelated noun meaning “a heap or stack of hay, grain, corn, etc.” or “a place, especially a part of a barn, where hay or corn is heaped up and stored.” This “mow” is also a very old word (“muga” in Old English) that comes from Germanic roots meaning “heap.” While we’re at it, “hay” meaning “grass cut for fodder” is a similarly ancient word, in this case going back to roots meaning “that which can be mowed,” presumably with a scythe or similar tool.
So a “hay-mow” is simply a heap (“mow,” the “rhymes with cow” one) of hay, which may or may not be stored in a barn. Strictly speaking, a pile of hay (aka “haystack”) in a field is also a “hay-mow,” though the term is so associated with a pile of hay stored in a barn that “mow” has also come to mean that part of the barn itself. As you’ve noticed, such a part of the barn, if elevated, is also known as a “hay loft” (“loft” being an Old Norse word meaning “air or sky” as well as “upper room”).
So there’s that, but here’s this: there’s also the curious term “mowhay” to consider, although you’re very unlikely to encounter it in the American Midwest. A “mowhay” is an enclosure (often a little shed or enclosed yard) used to store a “mow” or “mows,” heaps of hay, corn, etc. Interestingly, the “hay” in “mowhay” is not the fodder sort of “hay,” though that is often its contents. This “hay” is a very old English dialect word meaning “fence” or “hedge,” and comes, in fact, from the same roots that gave us “hedge” (which used to mean any sort of boundary or fence, not necessarily one composed of shrubbery). So a “mowhay” could as well be called a “hay-hay,” assuming you’re not afraid of being mistaken for Krusty the Clown.