If someone says they are under the weather, they mean they feel ill, unwell, or not quite like themselves—usually in a mild or non-dramatic way. That is the main meaning given by major dictionaries, and it is the sense people overwhelmingly use today.
Quick Answer
“Under the weather” means feeling sick, unwell, or slightly off. It is a common English idiom people use when they do not feel good but do not want to sound overly dramatic or give a lot of medical detail.
What Under The Weather Means
In everyday English, under the weather usually means someone feels mildly sick, tired, run-down, or generally not at their best. Collins defines it as slightly ill, and Merriam-Webster gives the core meaning simply as ill.
That makes the phrase useful for situations like:
- a cold
- a headache
- low energy
- an upset stomach
- general fatigue
- feeling “off” without wanting to explain more
It is often less direct than saying I’m sick and softer than saying I’m ill.
Why People Say Under The Weather Instead Of Sick
One reason this idiom stays popular is tone. Under the weather sounds gentler and more conversational than sick. LanguageTool says it is often used to indicate illness without going into too much detail, and QuillBot explicitly describes it as a euphemism for feeling sick.
That makes it especially useful in everyday situations:
- “I’m a bit under the weather today, so I’m staying home.”
- “She’s feeling under the weather and may join later.”
- “I was under the weather yesterday, but I’m better now.”
In each case, the speaker communicates the problem without sounding dramatic or overly personal.
Literal Meaning Vs. Figurative Meaning
Taken literally, under the weather sounds like being physically beneath rain, wind, or clouds. That is not what speakers mean.
Figuratively, the phrase means feeling unwell. Because the literal words do not directly explain the actual meaning, it functions as an idiom. LanguageTool’s explanation makes this point directly: the phrase’s figurative meaning is different from the literal meaning of the individual words.
When People Use It
This idiom is most natural when someone wants to describe mild or moderate discomfort in a casual, familiar way. Common situations include:
- calling out of work
- canceling social plans
- explaining low energy
- describing someone who looks unwell
- mentioning a short-term illness without detail
QuillBot notes that the phrase works in casual settings and even in some business communication, such as emailing a boss about being absent, while also noting that it is not usually the best fit for academic or medical writing.
Tone And Context
The tone is usually:
- informal
- mild
- polite
- slightly euphemistic
That tone is one of the phrase’s biggest strengths. It helps speakers sound natural and understated rather than dramatic. It is especially common in speech, texts, and casual emails.
It is less natural in:
- medical reports
- formal academic writing
- legal or technical documentation
- situations where precise language matters more than tone
In those settings, words like ill, unwell, symptomatic, or the actual condition are usually better choices.
Does It Always Mean Mild Illness
Usually, yes. In modern English, under the weather normally suggests something temporary and not too severe. Collins defines it as slightly ill, which captures the common tone very well.
That is why the phrase sounds natural for a cold, fatigue, or a headache, but less natural for a serious diagnosis or a major medical event. If someone is hospitalized or severely ill, under the weather may sound too soft or evasive.
Can It Ever Mean Something Else
Yes, but not usually in modern everyday use.
Merriam-Webster includes a secondary sense of drunk, and Collins and Dictionary.com also record older or less common meanings related to being drunk or having a hangover. That said, modern everyday usage overwhelmingly points to feeling physically unwell rather than intoxicated.
So if you are writing for a general audience today, the safest and most natural interpretation is still feeling sick or unwell.
Origin And History
The most common origin explanation is nautical. Britannica says the idiom is believed to come from sailing: when a sailor felt ill, he would go beneath the bow or below deck for protection from rough weather. QuillBot gives a similar explanation, linking the phrase to sailors going below deck or under the weather bow during rough conditions.
That explanation is widely repeated because it fits both the imagery and the meaning. At the same time, QuillBot also notes that recorded evidence for the exact wording in that original setting is limited, so the history should be presented as likely rather than proven in every detail.
Dictionary.com takes a broader view and says the phrase presumably alludes to the effect of weather on a person’s health, dating it to the early 1800s. That is another reason to keep the origin section careful: the general historical direction is clear, but the exact path is not perfectly settled.
Example Sentences
- “I’m feeling a little under the weather, so I’m working from home today.”
- “She looked under the weather during the meeting, so we kept things short.”
- “He was under the weather all weekend with a bad cold.”
- “I was a bit under the weather yesterday, but I’m back to normal now.”
- “The kids are under the weather, so we postponed the trip.”
- “Sorry I missed dinner. I was feeling under the weather and went to bed early.”
These examples show the idiom in its most natural register: everyday, mild, and conversational.
Similar Expressions
Close alternatives include:
- not feeling well
- feeling unwell
- feeling sick
- a bit off
- out of sorts
- run-down
These are not identical in tone. Under the weather is often slightly softer and more idiomatic than sick, and less vague than off. Merriam-Webster’s thesaurus also groups it with words such as ill, poorly, sick, and out of sorts, which reflects how native speakers understand its range.
FAQs
Does “under the weather” always mean sick?
Usually, yes. In modern English, it most often means feeling ill or unwell, especially in a mild or temporary way. That is the main sense given by Merriam-Webster, Collins, and LanguageTool.
Can it describe something serious?
It usually sounds milder than serious. It is a natural fit for a cold, fatigue, or feeling off, but it may sound too soft for severe illness or major medical problems. Collins’ wording—slightly ill—supports that more limited everyday use.
Is “under the weather” formal?
Not really. It is common in speech, casual writing, and everyday emails, including some workplace communication, but it is not the best choice for academic, medical, or highly formal writing.
Can I use it about someone else?
Yes. You can say, “She seems under the weather” or “He’s been under the weather all week.” Collins and common usage examples support both self-reference and describing someone else.
Can “under the weather” ever mean drunk?
Yes, in older or secondary dictionary senses. Merriam-Webster, Collins, and Dictionary.com all record that meaning, but it is not the main modern use. Today, most people understand the phrase to mean feeling unwell.
Conclusion
“Under the weather” means feeling ill, unwell, or slightly off. It is a common idiom because it sounds natural, polite, and understated, especially when someone wants to explain that they do not feel well without sounding dramatic or oversharing.
Use it in casual conversation, friendly writing, and everyday work communication when the illness is mild or temporary. For more formal or medically precise situations, clearer language is usually better.
