A thingamajig is what you call something when you can't remember its actual name or when you don't know what it's called in the first place. If your dad asks you to grab the thingamajig from the garage that tightens bolts, he probably means a wrench, but the word isn't coming to him. When your teacher points to a strange scientific instrument and says, “Hand me that thingamajig,” she's asking for the device even though she's temporarily blanking on its proper name.

Everyone uses words like thingamajig, along with its cousins thingamabob, whatchamacallit, doohickey, and whatsit. These placeholder words buy you time when the real word is stuck on the tip of your tongue. They're especially useful when you're pointing at the object you mean, so the other person can see what you're talking about even if you can't name it.

Interestingly, thingamajig works better in casual conversation than in writing, since you can usually take time to look up the actual word when you're writing. But in the moment, when you need to communicate quickly, thingamajig does the job perfectly well.