This is a poll. I’m interested in what people call something when they can’t recall or don’t know the actual name. I wonder if there are regional differences.
The one word that I think may be regional is “thingy”. Nobody but us Bronxites say “thingy”. So, please tell me what you say and where you’re from when you mean to say, um, thingamabob.
Dongle mostly. Don’t know where I got that term from.
Other terms less often used includes widget and thingie.
“Hey, hand me that thing! You know the <adjective> hootchie-cootchie. Yeah, that”
Or sometimes, “I’m looking for my <brainspaz>… metal… wrist… time-thingie. Have you seen it?”
Thing-a-majigee works for me.
Whatchamacallit works well too.
“Hand me the dongle, willya?”
That sounds ridiculously obscene.
I prefer “thingie” but also use “doo-dad”, “thingie-mic-bob(er)”,“thingie-mic-doodle”, “whatzit”, and “who-the-what-now?”
Exactly. 
I say thingie. And whatsamawhoozit. And diddly-bob.
“Honey, gimme the…uh…the uh… (makes descriptive gesture with hands) the DIDDLY-BOB!”
Dealie-bobber. Also gizmo, if it has moving parts. Don’t ask me why.
There is the famous left handed catawumpus.
I’ve also heard of the not so famous humma-ding-ding.
Um, I’m not a Bronxite, and I use “thingy” all the time. Usually along with a very vague description of what i’m trying to say… as in “pass me that channel-changing thingy”.
Yep, we use “thingy” here too, along with it’s more formal forms, thingie-mah-bob and __________-thingy when being descriptive.
I kind of gave up on “Whatchamacallit” when they made a candy bar named that, felt vaguely wrong after that.
Doo-hickey is probably the one I use most often when frustrated yet trying to refrain from profaning. 
Hoobeedoo
“…the thing/guy/person/place…”
Or: “you know what I’m thinkin’ about, don’tcha?” To which the answer is always no.
whatchamacallit
A combination of Whatchamacallit and Thingamabob:
“Whatchamabob”
I too, Queen Tonya, don’t like using the word (or whatever these things are called) Whatchmacallit ever since that candy bar came along. It kind of killed the word for me…well, to an extent…since I still do use the first part.
Or
“That thing…whatever you call it”
Hoochajiggy or hoochamajiggy. Less often whatchamacallit or thingamabob.
My husband says hoochajiggy for mechanical-type things and whatchamacallit for everything else.
We were both raised in Chicago.
We knew someone from Rhode Island who said reebadoo, but suspect that might have been hers alone…
My mother-in-law frequently refers to things she can’t remember the names of as “hoo-hoos” - as in “I made a batch of those chocolate raspberry…um… hoo-hoos.”
Furniture used to be referred to by her as “the thing in the room…with the thing… in the corner… you know, where I always put those hoo-hoos at Christmas?” Now she thinks it’s entertaining to call furniture the “henway” – which of course prompts her son, my dear dim WryGuy, to inquire, “What’s a henway?”
Mom says, “About three pounds, give or take.”
Anyone else got that song Part of Your World from The Little Mermaid now running through your head? You know…the one that goes like this:
I’ve got gadgets and gizmos aplenty
I’ve got whozits and whatzits galore
(You want thingamabobs? I got twenty)
But who cares?
No big deal
I want more…
Thanks, Biggirl, now I’ll be singing that all night.
I came across one or the other of these two words in the dictionary. (American Heritage I think)
Doo-dad
Thingamabob
Anyhow, the words definiton was the other word.
I didnt look up the other word. (I wasnt looking up the first word either, just saw it on the page)