I had never seen hawmow either, although I was familiar with haymow, a synonym for hayloft. Googling tells me it is a legitimate variant, but an old one, probably near-obsolete today.
Hitting the youtube sites that come up under “haymow pronunciation,” I get two hits for rhymes with cow and one for rhymes with throw.
Using it in a sentence: the cow throwed up the hay in the hawmow.
Apparently at least some dictionaries consider “haymow” to refer to either a barn, loft, or shelter of some kind to protect stored hay from the elements.
Or to refer to a haystack out in the open. Which I suppose is a very primitive way to protect the hay in the center of the pile by using the exterior layer(s) of hay as a sacrificial sheathing.
Not a word I’d ever encountered before today.
For some reason, this thread reminds me of one of those fake letters that National Lampoon would run:
To the editors,
I understand that in the last year of his life, Lou Gehrig couldn’t tie his shoes. Shoot man, I cleared that hurdle when I was twenty three.
Signed,
Mr. T.
I’d never encountered “haymow” before either. The OED gives only the rhymes-with-cow pronunciation. The second syllable is unrelated to the verb “mow”; rather it is an obsolete or regional word, rhyming with “cow”, which means a heap of grain or hay (pretty much what “haymow” itself means). It comes from a Germanic root meaning “heap” or “crowd”, with cognates in Norwegian, Old Icelandic and Old Swedish.
Also the big bales that look like marshmallows that you may see, are also composting that stuff. Fermenting the plant matter, breaking it down, making it more digestable, and probably a bit alcoholic.
Happy cows are good cows.
For whatever reason, we differentiated silage from haylage. Silage, to us, was cornstalks and cobs left to ferment.
As an American, I’d only heard farmers call them haystacks, and only as memories of the old days before it was exclusively baled and stacked in the barn loft. This too was years ago, before the modern practice of rolling hay into giant shredded wheat biscuits wrapped in plastic.
Only when I cracked into old English Lit. did I encounter haymows (rough lumps of newly-mown hay), that would be transported in haywains (a vehicle beloved by William Wordsworth on his nature walks) to be stored in hayricks; which, according to Far from the Madding Crowd, should be resistant to fire if properly packed. Moving from Thomas Hardy to Rudyard Kipling, there was the Sudanese Ansari, “with your 'ayrick 'ead of 'air”
Yeah, it’s kimchi for cows. But it’s the only use for a silo. Anything else and it’s a grain bin.
Don’t you remember that old song, “Haymow, haymow, it’s finger pop - popping time…”
When I was 15 I worked on a couple of farms in Southern Ontario, helping harvest hay. After loading the bales onto a wagon we’d stack them in the lofts of the barns, which the farmers called mows. Now, having just turned 70, I find that some people miss-spell this as maw.
Obvious, but: it only just dawned on me that Shakespeare more or less had Mark Antony heroically do the same thing that Iago did villainously…
The more I read the word haymow, the more I “hear” it with my grandfather’s voice. As he had barns, which had hay in them at some point, he might have used the word haymow. I have to ask my parents if they know the word.
Maybe you have to be Ohion to know about haymow.
My neighbor has Ikea shelves from 1995 or so, which she bought in Germany. She’s moved a few times with them.
A farmer friend in southern Ontario uses “haymow” to this day. It refers to the hayloft in the barn. A “hayrick” was the trailer we used to transport the baled hay from the place we got it, back to the farm.
I’m 44 now, and it’s only a few years ago that I learned that the word “segue” is pronounced SEG-way and not SEEG. Prior to that, I thought “Segway” was just the vehicle and perhaps somebody’s surname it was named after.
Heymow, heymow
Don’t dream it’s over
Heymow, heymow
When the world comes in…
Ninjaed! One of my all-time favorites…and a huge reminder of my late wife, as she always turned up the radio when it came on.
I wrote the word on a piece of paper and asked them about it. Definite yes and they were surprised to get the question as they expected that I should already know the word.
They pronounce haymow to rhyme with cow, and consider it to be a synonym to hay loft. I also got an instruction from my dad about how to put hay into the haymow. 
Sorry I didn’t get back to this thread sooner! Hawmow is indeed a typo. I meant haymow.
And @Dinsdale was however old he is now when he learned that Rebo is a woman!
(bolding mine)
ETA: And I typo’d the dang word again! I fixed it. I originally wrote hawmaw.
Came in here to say pretty much this, except I had thought that “segue” was pronounced like the first syllable of “segment”.
Wanted to see what Bing/Dall E thought a “hawmaw” was, but it knows what a haymow is and wasn’t confused by the typo.
I thought it was “fan mail”. What do I know, I hate that song. And Skinnerd.
I actually thought the word was “hay mound”.
I grew up on a farm. We didn’t have haymows (rhymes with cows) but the more, shall we say, old school farms nearby did. I’ve never seen it written out before today.
We never made silage. Our silo was a thirty foot high brick cylinder with a dirt floor. I think it was built in nineteen aught three. It became the defacto home for pigeons.