What’s the Word for When You Can’t Remember a Word?

In terms of humor and ingenuity, momentarily forgetting a word is the gift that keeps on giving. Soup has been “wet salad.” A reservation has been a “food appointment” and a menu has been a “food syllabus.” The absence of dryer once produced “tumble-oven.”

There are plenty of informal ways to describe this phenomenon. You drew a blank. The word was on the tip of your tongue. You had a brain fart or a mental lapse. The rat under your hat took a smoke break.

But if you’re looking for something with a fancy, academic edge, the word you want is lethologica.

Lethologica: Origins and Meaning

Lethologica derives from two Greek terms: lēthē, meaning “forgetfulness, oblivion,” and logos, meaning “word.” Greek mythology enthusiasts will no doubt recognize its connection to the River Lethe, which the recently deceased would drink from as they passed into the underworld, forgetting their memories of mortal life.

It’s unclear where the word itself came from. Credit sometimes goes to Carl Jung, though nobody has been able to identify where he ever used the word. The earliest known reference to lethologica is in a 1914 edition of Dorland’s Illustrated Medical Dictionary, which aptly defines it as the “inability to remember the proper word.”

Despite its century-old print debut in a medical text, lethologica isn’t considered a medical condition in the same way that anomia—“loss or impairment of the ability to name objects,” per the American Psychological Association—is. Anomia is an ongoing issue that’s often a symptom of aphasia, a broad category of communication and language difficulties related to brain damage or a brain disorder. Lethologica, on the other hand, is an isolated incident that’s just part of the human experience.

In fact, the word lethologica isn’t recognized by Merriam-Webster, the Oxford English Dictionary, or the Cambridge Dictionary—nor is lethonomia, an offshoot that specifically describes not being able to remember someone’s name. Even Dictionary.com, which has an article about the two terms, doesn’t list either in the dictionary itself.

But lethologica does occasionally crop up in studies investigating what causes the thing itself. Often, researchers refer to it by a less academic moniker: tip-of-the-tongue phenomenon (or state or syndrome), a.k.a. TOT.

The Psychology Behind Lethologica

Lethologica occurs when there’s some kind of hitch in your brain’s word retrieval process—but researchers aren’t exactly sure what that hitch is or what causes it. TOT is generally thought to happen more when you’re tired, and studies have shown that older adults experience it at higher rates than younger people. It’s not a foregone conclusion that cognitive decline is to blame—at least one study has suggested that it could have to do with older adults simply having more knowledge.

Though studying something that happens seemingly at random is tough, researchers have found that they can generate TOT states by giving participants definitions to words that they probably don’t use in their daily lives—for example, from one 1966 study, “a navigational instrument used in measuring angular distances, especially the altitude of sun, moon and stars at sea.” Researchers realized that some participants who couldn’t think of the correct answer, sextant, could often still come up with a word that wasn’t too far off—be it a related word, like astrolabe, or a word that just sounded like sextant (such as sextet or sexton).

If we can get that close to the finish line, why is it so hard to cross it? One possible explanation involves implicit learning: If you unwittingly pick up a new word, the connection between the word itself and what it means might not be as strong as it would be if you intentionally learned it. But considering that TOT states often happen with words as common as soup and dryer, it seems like there must be more to the story; in short, more research is needed. 

Some research suggests that you may be more likely to experience TOT states with the same words repeatedly if someone (or the internet) always just tells you the answer. Instead, you should ask someone to give you the first few letters or some other phonological hint so you can figure it out yourself. Actually producing the word, even with a clue, might help create a stronger connection in your brain than just hearing or seeing it.

But there’s not always time for a guessing game when lethologica strikes in the middle of a busy diner—in that case, go ahead and ask your server for the food syllabus.

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