The familiar problem
You meet a word in a report or an article. You look it up. The definition makes sense, you nod, and you carry on reading. A week later the same word turns up and it feels familiar, but you cannot quite say what it means. You look it up again.
This is not a sign of a bad memory. It is what normally happens when the only thing you did with a word was read its definition. There are four reasons, and each one points to a fix.
1. Recognition is not recall
Knowing a word has two levels. Recognition means you see the word and something feels right. Recall means you can bring up the meaning on your own, or reach for the word when you need it in your own writing.
Reading a definition builds recognition. The next time you see the word, it feels known. But that feeling is easy to mistake for real knowledge. When you need the word in an email, or need its exact meaning in a contract, recognition is not enough. Recall is the skill you actually want, and reading a definition does very little to train it.
2. The dictionary gives you every sense, not the one you need
Most common English words have several meanings. Take run, address or issue. Even less common words shift with context. Exposure means one thing in a finance report, another in a medical article and another in photography.
A dictionary lists the senses in its own order. You scan the list, pick one that seems to fit, and move on. If you picked the wrong one, you have now stored a meaning that does not match what you read. If you picked the right one, you have still stored it next to five others that blur together. The meaning that matters is the one in your sentence.
3. A definition has no context
Words are remembered through what surrounds them: the sentence, the topic, the writer, even why you were reading. A definition strips all of that away. "To make something less severe" is accurate for mitigate, but it is abstract and forgettable.
Compare it with the sentence where you found the word: "The new process should mitigate the risk of late payments." Now the word has a job, a partner (risk) and a setting. That sentence gives your memory several hooks instead of one. It also shows you the word's usual company, which is what you need when you want to use it yourself.
4. Nothing makes you retrieve it later
This is the biggest reason. Memory gets stronger when you pull something out of it, not when you put it in again. Psychologists call this the testing effect, or retrieval practice. In one well-known study, students who took a practice test on a passage remembered more of it days later than students who spent the same time rereading it (Roediger & Karpicke, 2006). A later study found the same pattern with foreign-language word pairs: repeated testing, not repeated study, drove long-term recall (Karpicke & Roediger, 2008).
Timing matters too. The spacing effect is one of the most reliable findings in memory research: practice spread out over days beats the same amount of practice crammed into one sitting. A large review of studies on verbal learning confirmed it across many experiments (Cepeda and colleagues, 2006). A quick look-up gives you one exposure, at one moment, with no retrieval at all. It is close to the weakest way to meet a word.
What to do instead: a four-step habit
None of this means you should stop using a dictionary. It means a look-up should be the start of learning a word, not the whole of it. Here is a routine that takes about a minute per word.
| Step | What you do | Why it works |
|---|---|---|
| Meaning in the sentence | Find the one sense that fits the sentence in front of you. Ignore the others for now. | Stops you storing the wrong meaning or a blur of meanings. |
| Save the sentence | Keep the word with its sentence and where you found it, not just the definition. | Gives memory context and shows how the word is really used. |
| Test recall later | A day or two later, look at the word and try to say the meaning before you check. Repeat at longer gaps. | Uses retrieval practice and spacing together. |
| Reuse it | Write it once in your own sentence, in an email, a note or a message. | Moves the word from recognition towards active use. |
Choose fewer words
The habit only works if the list stays small. Do not save every unfamiliar word on a page. Save the ones you are likely to meet again or want to use: words from your field, words that keep appearing, words you would like in your own writing. Five well-kept words a week beat fifty saved and never seen again.
Make the test honest
When you review, cover the meaning and commit to an answer before you look. If you just glance at the word and think "yes, I know that", you are back to recognition. Mark the words you got wrong and see them again sooner. Words you get right easily can wait longer.
Look inside the word
Roots and prefixes give you another hook. Mitigate comes from Latin mitigare, built on mitis, "mild" or "soft". Once you know that, "make less severe" feels less arbitrary. Our guide to root words and etymology covers the most useful ones.
For a longer version of this routine, with tips for choosing words while you read, see how to remember new English words while reading online.
How Stemmy fits
You can run this habit with a notebook and a calendar. Stemmy is a free Chrome extension that keeps each step close to the page you are reading.
When you highlight a word, click the Stemmy button beside it or press Alt+Shift+D, the Ghost Card shows the meaning that fits the sentence, the word's roots (WordDNA) and its pronunciation. That covers step one and gives you the root hook at the same time. AI meanings need a free account, which comes with 150 free AI uses.
Saving a word puts it in your Vocabulary Wallet with its meaning, the source sentence and the page link, so step two takes care of itself. You can search your words, grouped into categories, in the side panel or the dashboard.
Reviews handle step three. They are short spaced-repetition sessions that cover only the words that are due, and you rate each one Again, Hard, Good or Easy. If you stop halfway, you can pick up where you left off.
Step four, using the word yourself, is still your job. Stemmy helps you meet the word again in new places first. AI Stories, which also runs on your free account, writes short passages from the words in your review queue, so you see them working in new sentences. If you turn on Immersion, your saved words appear again on pages you read, with one click back to the original text.
AI features need a free account (Google Sign-In or email). Each account gets 150 free AI uses in total, once; Ghost Card lookups and cloud voice draw on them. Free to install. No paid plan is offered today. Your wallet, reviews and settings are stored in your browser; the privacy page explains what is sent and when.
Frequently asked questions
Should I stop using a dictionary?
No. A dictionary is the right tool for checking a meaning. The problem is stopping there. Treat the look-up as step one, then keep the sentence and test yourself later.
How many new words should I try to learn at once?
Fewer than you think. A handful of useful words a week, reviewed properly, will usually stay with you longer than a long list you never revisit.
Is it better to learn a word from a sentence or from a definition?
Use both, but anchor the definition in a real sentence. The sentence shows the right sense, the words it usually appears with and the tone, which a definition alone cannot.
How long should I wait between reviews?
Start with a short gap, such as a day, and make each gap longer when you remember the word easily. If you forget it, shorten the gap again. Spaced-repetition apps work out these intervals for you.