I have a friend who loves to take the mickey out of his kids’ latest slang. About ten years ago, it was trendy to say “snap”. My friend immediately latched on to this and when ever he could, he’d say something was “snaptastic”. Needless to say, the kids didn’t use “snap” for long.
In our group of friends, we have been saying “snaptastic” ever since then. Always makes me smile. The kids, all adults now, roll their eyes.
@CountingDown - so funny about invoking counsel!
I love all of these, but especially, “five more handfuls” and “going upstairs” and the whale story!!
Thanks for sharing!
@Sue22, our kids called it 'sprinkle cheese!"
Others:
“Take chances, make mistakes”
“You are a very Useful Engine”
One of my nieces had a hard time pronouncing her ‘r’ sounds when she was a toddler. This led to a rather interesting Thanksgiving when she loudly demanded a fork. It is part of the family tradition now…
I still have a copy of the Yom Kippur book and have also scanned it for posterity. When the guys were still home and we’d watch L&O or NCIS, they would always yell at the hapless suspect spilling his/her guts to shut up and ask for a lawyer!
Thanks to my late brother we always call the glove compartment in the car “the conglovement.”
I still enjoy seeing the fingle mingles at the zoo, which is the first term DS used for flamingos.
We got a lot of our sayings from D2 because she was so verbal as a toddler and she was the baby - 5 years younger than her sister.
She loved chocolate milk when she was little. We tried to ration her, and it was not hard to see the joy in her face when it was offered to her. When she was 3 or 4, we drove by a farm with a lot of brown cows in the pasture. D2 just blurted out, “Chocolate milk cows.” We all stopped more a minute before we realized why she called them chocolate milk cows. Since then we have called all brown cows that.
About the same age, D2 complained to us how my father always took “long cut” when driving her to ballet class. We then started saying (whenever we are lost), “are we taking a long cut?”
D1 used to get chicken and kitchen mixed up. For a while we would call kitchen chicken sometimes.
My favorite saying when people complain too much to me, “It could be worse.” This came about when my senior management was complaining to me about the fact we didn’t have disaster recovery at a site I was responsible for, and numerous other problems with the site. It was about a month after I took over. I got tired of listening to the complaints, so it just came out. My staff thought it was hysterical and they started to say it. My kids also picked up on it too because I would say it to them when they thought their world was coming apart.
My family used to watch the BBC show “Keeping Up Appearances” when the kids were young. “More tea, vicar?” is our go to phrase to cover the stunned silence when someone does something embarrassing or gross.
From Monty Python and the Holy Grail - no matter how bad something is, one of us will say: “It’s only a flesh wound.” It came about when one of my sons broke his leg very badly and was laid up for the summer. He became convinced he would lose his leg and his brothers comforted him by saying, “Don’t worry, it’s only a flesh wound.”
My wife’s go-to when our kids do or say something dumb: “That must be your Daddy’s genes”. I hear that comment almost everyday. My kids even say it to each other now. I really should tell their loving Grandparents about this betrayal…
We are Jewish. Most people we know our Jewish. So when our family was invited to our friends wedding we prepared our young kids for what to expect in a Catholic church. We explained that it was very similar to going to Synagogue. You had to dress nicely. The priest would be at the front and in charge etc…
So we get there and as it’s about to start our then 3 year old says “ who is that guy up there?” And we say “ remember that’s the Priest. He’s like our Rabbi. He…”. And she interrupts “No not him. The guy on the T!” Who is that?”
Suffice it to say that we may or may not refer to Jesus in our house as “The Guy on the T”
When my younger sister was in HS, she took a trip to visit a faraway friend. Parents and I picked her up at the airport, and our dad—a very terse and emotionally repressed guy—found an interesting way to break the news that the family pet had been euthanized while she was away. He turned to her with a meaningful look and asked:
“Was the cat sick when you left?”
This phrase gets a lot of play in both our families.
We have so many! I don’t even know what to pick. We even have picked up some from our dog! If someone really wants something from another member of the family, we’ll mimic our dog’s head tilt, open our eyes wide, raise our eyebrows, and give a little whimper. 
Our D called broccoli “little trees” when she was a baby. That has stuck.
We also have code words when people are being pretentious based on a long repeated family story.
My dear father used to say “You can do it the right way or your own damn way.” And he said it with a completely neutral tone. The thought of it still brings a smile.
A friend of ours calls sweet potato fries orange fries!
As food/leftovers get eaten, my mom puts them in smaller containers… we call it “Grandma’sFirstName”-izing!
From Cool Runnings - my DH used to IM the college kids with ‘Sankamon, you dead?’ when we hadn’t heard from them in a while. Now, I text the same.
@mominva - I learned “POL” (proof of life) from these boards. I often tell ds, “Don’t make me send you the POL text!”
Whenever things are chaotic (or once in a while at times when they are particularly serene or scenic) we say “How’s the serenity?” from the Aussie movie The Castle
My younger brother was enamored of horses when he was about 5. If we drove past some horses, he would greet them with an enthusiastic “Hi, guys!” One day, he greeted some large mammals: “Hi, guys! Oh, they’re cows.” For some reason, that stuck as a family allusion, and to this day (45 years later), I still say (if only in my head), “Hi, guys! Oh, they’re cows,” every time I pass some bovines.
My dad’s family had some big eaters (the thin kind - wish I had that gene!) and some critics (got that gene). One of their family allusions that was handed down was tasting something, pronouncing it terrible, and then continuing to eat a lot of it “to find out how bad it is.” 
When our S was a toddler, he woke from his nap and declared he wanted “socks.” I was very puzzled and handed him some socks and he stared at me baffled and said emphatically , “No, not this, you know, SOCKS!” I was very puzzled until he led me to the kitchen and I figured out we wanted “snacks!” Luckily for him we never made that a family byword.
My mom was very resistant to wearing hearing aids, and when she finally did get them, she often forgot to turn them on. My cousin was visiting and we were having a discussion at the dinner table about a subject Mom was very interested in, and she seemed engaged, smiling and nodding… at one point my cousin asked her “What do you think, Auntie?” Mom gave us a quizzical look and said “Tuna fish?”. Apparently she thought we were discussing something quite different! So now whenever there’s a family gathering and there’s a discussion we want to avoid (like politics, religion, or very personal questions), we make eye contact and say “Tuna fish?”.
A few years ago we vacationed at a cottage in Maine and the owner of the place lived across the road. On the first day, we had a number of technical challenges (front doorknob fell off, toilet wouldn’t flush, shower only ran cold water). Each time we reported an issue to the owner she looked at us sternly and said “Hmmm… the people before you didn’t have any problems”. So now whenever there’s a mechanical or technical issue in our house… that’s what we say.
When someone is being super braggy /pretentious, we say “Don’t be Jack’s dad”. Jack and his dad were on a college tour with us (we didn’t know them) and he kept making comments to the guide like “Jack is incredibly advanced/talented in (this or that), I wonder whether your offerings in this area will be enough for him”.
When my daughter was a toddler, she called any kind of pasta “noolies”, and we still call it that in our house. 