A former boss was always telling me that she would “just assume” do A instead of B.
In the South, a person who was thought to be anti-religious or of questionable political leanings was called a commonist (communist).
Also, a male who exhibited female characteristics was referred to as a morphodite (hermaphrodite). That term was used in “To Kill A Mockingbird.”
Hah! I have one of those…I am so stealing that!
Since it’s MapPlethorpe, by making that association, you’ve still sort of managed to fit in here. 
My wife and I had caught nine fish on a slow day. We got back to the dock, where somebody asked “How’d ya do?”
She said we caught a dozen. I raised an eyebrow, and she said, “A fisherman’s dozen!”
I told one my next door neighbor that I had termites and he said he was giong to look them up on the internet to make sure he didn’t have them too. The very next morning I saw him outside cutting down his stand of beautiful mimosa bushes. I asked why he was doing that, and he said, “I read that those mimosa termites were moving into the area and I don’t want them anywhere NEAR my house!” I am pretty sure he read about Formasan termites, and then screwed it all up. My wife and I still laugh about it and ask him if he has seen any “mimosa” termites lately.
One I hear (and read) frequently, in fact it seems to be becoming almost “accepted” is:
He did it off his own back
instead of “bat”, meaning “on his own initiative”.
HA HA! Are you kidding me? That’s what I’m going to ask for next time I’m at IHOP!
I don’t know why, but this one really gave me the giggles.
~wiping tear away~
Yes, that’s what I started this thread with. "Keep your eyes peeled " is how I’ve always heard the phrase. This is the same guy that would say “The shit really hit the stick on that one!” Isn’t the shit supposed to hit the fan?
I think he was confusing that with getting the “short end of the stick”.
E3
Oh, man, I feel for the minister, I really do. I seem to have this problem mostly when leading circles in ritual. I’m trying so hard to set a mood and have it all nicely balanced between somber and sacred and fun and mystical, and then I proceed to announce that we’ll be calling “The Four Holy and Sacred Elephants!” in each direction. :smack: (Elements, ELEMENTS.)
I used to work in payroll and one day an employee called me and said “a friend just told me we get paid in the rear. What does that mean?” After muting my phone for a few seconds so I could laugh, I told her that although it may feel that way sometimes, you’re actually paid “in arrears,” meaning your paycheck reflects the last 2 weeks worked, or in other words, you aren’t paid in advance.
My SIL’s sister once asked my brother, who was headed to Las Vegas, if he was going to see Sigmund & Freud.
My sister once had a boss who said “aggregated” instead of “agitated.” We, of course, have now apropriated this. When one of us is generally fussing and fuming about something inconsequential, the phrase “I just get so damn aggregated!” will be used.
And how many of us have heard someone talking about the prostrate gland?
There are some people, (even one on this board), who think the phrase is “I tried my damnedness.”
Just this week, Tony Soprano said he was prostate with grief.
A friend of my dad’s once couldn’t remember the word “Alzheimer’s” and said Azaleas instead. She knew it was wrong immediately, though. From that time on, whenever you can’t remember anything around my dad, the joke is that you have “Azaleas” or it’s “that Azaleas kicking in again”.
I thought I heard it in the film Stand by Me as well.
I’ve heard quite a few people refer to the ailment as Old Timer’s.
Regarding “aggregated,” I had a college roommate who was a tad dim. I asked if I could read her People magazine I saw laying on her desk and she said, “Sure, anytime. I have a perscription.”
We (my then-boyfriend and I) howled over this and forever after had perscriptions to magazines and got our subscriptions filled at the pharmacy…to the point that when I wasn’t joking I had to stop and think what the correct word was! Also, now I wonder if anybody ever heard me say this and went home and told their spouse what a lout they overheard that day. 
It’s turtles all the way down…