under wear (underwear)

Quick answer

Write it as one word: "underwear." The closed form is the standard noun for garments worn beneath outer clothing. Writing "under wear" (two words) looks like a spacing error and can confuse readers.

Why "underwear" is one word

"Underwear" is a closed compound noun formed from the preposition "under" + the noun "wear." Over time English compounds often fuse into a single word when they refer to a single idea. In this case the fused form is both common and dictionary-standard.

Splitting it into "under wear" breaks that unit and can be read as two separate words (for example, "wear that is under something" or an accidental typo), so stick with the single-word form in most contexts.

Spacing and hyphenation: when anything else is acceptable?

Standard modern usage: one word-underwear. Hyphenation ("under-wear") is rare and typically appears only in very old texts or for stylistic effect. Two words ("under wear") is almost always incorrect unless the words truly function separately in the sentence.

Closed compound (correct): underwear
Hyphen (rare/dated): under-wear - occasionally seen in historical or stylistic contexts
Two words (usually wrong): under wear - looks like a typo or mis-segmentation

Grammar note: how meaning and form match

Compound nouns are judged by meaning and usage. If the combination names one thing (a category of clothing), it usually becomes a single word. Because "underwear" names a distinct category, the closed form signals that unity.

Only split the phrase when syntax forces separate roles for the words-for example, if "under" acts as a preposition and "wear" as a verb or separate noun in the same sentence: "Do not under wear your coat" is awkward and usually should be rewritten.

Real usage examples

Work:
Wrong: We need to order under wear for the uniforms.
Right: We need to order underwear for the uniforms.
Work:
Wrong: The locker room lacks clean under wear.
Right: The locker room lacks clean underwear.
Work:
Wrong: Please check the inventory of under wear sizes.
Right: Please check the inventory of underwear sizes.
School:
Wrong: The drama department asked for extra under wear for the costumes.
Right: The drama department asked for extra underwear for the costumes.
School:
Wrong: Students should bring appropriate under wear for the trip.
Right: Students should bring appropriate underwear for the trip.
School:
Wrong: Label your under wear to avoid mix-ups.
Right: Label your underwear to avoid mix-ups.
Casual:
Wrong: Did you pack under wear for the weekend?
Right: Did you pack underwear for the weekend?
Casual:
Wrong: He forgot his under wear at home.
Right: He forgot his underwear at home.
Casual:
Wrong: I need to buy new under wear.
Right: I need to buy new underwear.

Wrong vs right pairs you can copy

Use these simple swaps when you edit drafts.

Wrong: I bought some under wear yesterday.
Right: I bought some underwear yesterday.
Wrong: The donation box accepts under wear for charity.
Right: The donation box accepts underwear for charity.
Wrong: Keep your under wear in the top drawer.
Right: Keep your underwear in the top drawer.
Wrong: Any under wear must be labeled.
Right: Any underwear must be labeled.
Wrong: She bought under wear on sale.
Right: She bought underwear on sale.
Wrong: Showers and under wear are provided.
Right: Showers and underwear are provided.
Wrong: He prefers cotton under wear.
Right: He prefers cotton underwear.
Wrong: Store under wear separately from towels.
Right: Store underwear separately from towels.
Wrong: Hand-wash under wear only.
Right: Hand-wash underwear only.

How to rewrite problem sentences

Simply replacing "under wear" with "underwear" usually fixes the issue. Sometimes a small rewrite improves clarity or tone.

Original: The costume requires under wear that matches the outfit.
Rewrite: The costume requires underwear that matches the outfit.
Original: Volunteers donated many boxes of under wear.
Rewrite: Volunteers donated many boxes of underwear.
Original: Make sure the team packs under wear for the trip.
Rewrite: Make sure the team packs underwear for the trip.

When possible, prefer more specific terms (briefs, boxers, undershirts) if they fit the context: "pack briefs" or "buy undershirts" can be clearer than a generic "underwear."

A quick memory trick

Picture "underwear" as a single item you put on every day. Imagine slipping on the unit-this mental image helps lock the spelling as one word. Another cue: compare with similar closed compounds you use every day (footwear, headband). If the pair names one object, it tends to be closed.

Similar mistakes to watch for

When one compound gets split, nearby words often do too. Scan your text for other split compounds and decide whether each should be one word, hyphenated, or separate.

footwear (not "foot wear")
notebook (not "note book")
everyday (adjective) vs. every day (adverbial phrase)
check for hyphenation in compound adjectives (e.g., "well-known author")

FAQ

Is "under-wear" ever correct?

Occasionally in older or highly stylized writing, yes, but modern standard English favors "underwear."

Can "under wear" be grammatical?

Only if "under" and "wear" truly act as separate words with separate grammatical roles, which is rare. Most of the time it's an error.

Should I capitalize "Underwear"?

Capitalize it only at the start of a sentence or in titles where capitalization rules apply; otherwise keep it lowercase.

Do British and American English differ here?

No-both varieties use the closed form "underwear."

How can I find all instances in a long document?

Search for "under wear" and "under-wear" and replace with "underwear" after checking context. Also scan for related split compounds while editing.

Check the whole sentence before you send

Small spacing errors stand out in isolation but become obvious in context. Read the full sentence, correct the compound, and consider a more specific word if it improves clarity.