The entry for "dust" from LDOCE says:

dust1 (n.)

  1. [uncountable] → HOUSEHOLD dry powder consisting of extremely small bits of dirt that is in buildings on furniture, floors, etc. if they are not kept clean:

    All the furniture was covered in dust.

  2. [uncountable] → HOUSEHOLD ...

  3. [uncountable] → INDUSTRY, HARD SCIENCE ...

  4. a dust (BrE) → CLEANING the act of dusting something:

    I need to give the sitting room a dust.

  5. ...

dust2 (v.)

  1. → CLEANING to clean the dust from a surface by moving something such as a soft cloth across it:

    Rachel dusted the books and the bookshelves.

  2. ...
  3. ...

Now, the entry for "undust" from Wiktionary says:

undust (v.)

  1. (obsolete) To free from dust.

I do notice the entry being marked as "obsolete" for undust, and also I remember my English classes as a child where we had a rectangular cubic sponge called a "duster" that we used to dust/undust the chalk on the blackboard, however every time I'm cleaning my desk, computer, furniture, etc. I'll automatically think of "undusting" and then will force myself to undo and say "dusting" instead, just to convince myself that the latter is the grammatical one; however I can't see the logic behind this verb and its usage based on general English grammar.

Google Ngrams also shows up some results (even if not many) for undust:

A usage frequency graph for "undust". The first, and highest, peak occurs around 1883, then it drops back to zero for a few years, then there's a bit of activity between 1903-1943, then another gap, then a slowly-increasing curve from ~1960-1998, after which it  tails off (but doesn't go down to zero).

Is undust incorrect? Did it exist as a correct verb years ago, and can I still use it?

I feel paranoid to say: "I'm dusting my keyboard!" because it makes me feel that it has the opposite meaning, as if I'm spreading dust and particles on my keyboard, especially since these chores aren't all that commonly spoken with today's lifestyle, and stating the former sentence might sound a bit odd.

P.S. Note that "dust something off" is slightly different in usage e.g. "They were dusting off leaves and twigs.", and based on my understanding from the definitions in dictionaries, saying "I'm dusting my keyboard off." isn't correct.

  • 1
    Contextually "I'm dusting my keyboard!" is appropriate and acceptable as it refers to the act of dusting. I've never heard the word "undust" used. A variation I've come by is "dust off".
    – MegaMark
    Aug 11, 2014 at 9:39
  • 1
    What's unclear about dust² = "to clean" and undust (obsolete)?
    – Andrew Leach
    Aug 11, 2014 at 9:43
  • @MegaMark Yeah, but "dust something off" is slightly different, since it indicates that you're removing that something off by dusting it. e.g. They were dusting off leaves and twigs.
    – Neeku
    Aug 11, 2014 at 9:43
  • 2
    On the lack of undusted in LDOCE, surely it is still a contemporary usage for ... If you're desk is covered in dust, and you dust it all off except for your keyboard, you have left you're keyboard undusted. (DV not from me - in fact +1)
    – Frank
    Aug 11, 2014 at 10:07
  • 1
    Even in the (presumably now always) current version of OED online undust is not marked as obsolete. I can't make an answer (of sorts) because I can't copy from the OED due to copyright restrictions. If you want to collect my comments up and add them to your question feel free. I'd trust OED over LDOCE. undust might not be in common use but obsolete seems harsh.
    – Frank
    Aug 11, 2014 at 10:38

2 Answers 2


Undust is used so little that you should indeed see it as obsolete. That ngram shows some results is not really relevant if you compare it with the occurences of dust.

Your paranoia is uncalled for, there is really no proficient, let alone native, speaker of English that will think that dusting your keyboard is similar to watering your plants.

I can understand where your hesitation to use it comes from, as you seem to be saying to opposite of what you are doing. Actually, to complicate matters, dust is used in the sense of adding dust as well: lightly dust the cake form with flour.

In context, however, there will usually be absolutely no confusion. When you dust your keyboard, everyone will understand that you are cleaning it.

As to the logic behind one word meaning two different (opposite) things, we are talking about English, the language that uses words like inflammable, and in which people say I could care less when they mean the opposite. Don't get stuck too much on logic when it comes to natural language!

  • 1
    True - to avoid the nouns, try comparing dusting and undusting . They can only be verb-forms, and undusting doesn't appear at all. (My browser spell-checker doesn't accept undust and undusting btw...)
    – oerkelens
    Aug 11, 2014 at 9:48
  • 1
    @Neeku - those words are a matter of American vs British spelling :) If you tell your browser that you want to use AmE, then "humour" is not correctly spelled...
    – oerkelens
    Aug 11, 2014 at 10:21
  • 1
    Neeku -- regarding the fact that "dust" can mean two opposite things. This is utterly unsurprising and normal in English. You can give any number of examples like that where, "logically" a word does "not make sense." It's just no big deal; it's irrelevant and normal in the language.
    – Fattie
    Aug 11, 2014 at 10:50
  • 1
    +1 Perhaps the most pertinent point: "Don't get stuck too much on logic when it comes to natural language!" Aug 11, 2014 at 16:18
  • 3
    In the same vein, consider the difference between watering a cow and milking a cow.
    – Bobson
    Aug 11, 2014 at 17:36

"undust" is obsolete at best, or more likely just "not a word".

"Is undust incorrect?" Yes, it's that simple: undust is incorrect.

"can I still use it?" Absolutely not, you quite simply can not use it. It's that simple.

Note: You seem to have found "undust" in "wikitionary". You can dismiss "wikitionary" as a language source, it's just an unlike scribble board.

Note: There's a great danger on this site: here, a speaker learning English is asking: "Hey I saw this weird word 'undust' mentioned, is that a word??" The full and complete answer has two letters: the answer is "No".

Of course, one could have an arcane discussion about how often that typo is used, was it a word historically, does it occur in print, etc. But it's really just plain not relevant. In the fullness of the question, the sense of the question, the answer is just "no, that's not a word dude."

  • 5
    I'd certainly label it 'obsolete' in spite of the OED stance. Other dictionaries label it so, and the OED isn't infallible. Perhaps they're picking up perverse usages such as that contrived for Amelia Bedelia. Aug 11, 2014 at 11:35
  • Right - heh good one on Amelia :)
    – Fattie
    Aug 11, 2014 at 11:51
  • 1
    According to dictionary.com, Webster's Revised Unabridged Dictionary also contains the word "undust", marked as obsolete.
    – Simon B
    Aug 11, 2014 at 12:10
  • 1
    @EdwinAshworth I never imagined I'd find Amelia Bedelia being used as an example of perversion! What a day!
    – talrnu
    Aug 11, 2014 at 13:51
  • 4
    There is no danger. This site is specifically not for people learning the language and is for "arcane discussion". Especially when it pertains to an obsolete word and not a typo as you incorrectly labeled it. Also note that the OP is asking whether it was ever a word so your answer is not really helping.
    – terdon
    Aug 11, 2014 at 16:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.