Hyphenating an adjective composed of two words is, from what I understand, fairly straightforward: if the adjective is before the noun, it must be hyphenated

The three-eyed raven
Customer-centric organizations

(with some exceptions such as not hyphenating after adverbs ending in -ly)

A highly efficient team

But how would one apply this to create an adjective from a composed word or expression and an adjective or past participle ? The example that comes to my mind is the following sentence:

Your product is based on big data

Which of these two options, if any, should I use, and why?

A big-data-based product
A big data-based product

Reading this, I think the second option does not mean what I want it to mean (it means that the product is big and based on data, not based on big data). The first option seems to make more sense, but is it correct?


2 Answers 2


The question begins:

Hyphenating an adjective composed of two words is, from what I understand, fairly straightforward: if the adjective is before the noun, it must be hyphenated ...

But this premises is quite incorrect. Mere grammatical form never mandates hyphenation. As the linked articles indicate:

When the meaning is clear without using a hyphen, it need not be used. In many cases this will mean that a hyphen will be sued, because many compounds can be read in multiple ways. But long familiar compounds will tend to drop the hyphen, because other meanings become improbable when a stand compound becomes a fixed phrase.

Incidentally, the APA link suggests hyphenating all words of a multi-word compound adjective. This means that "A big-data-based product" is not only permitted, but favored. Specifically the APA page says, under "General Principle 2":

Also use hyphens for -- Compounds in which the base word is:


more than one word: non-achievement-oriented students

  • Thank you. Your first link states that hyphenation (as I tried to describe it in my question) is expected in the UK, and that this rule is less stringent in the US. However, both your first and third link only give examples where hyphenation does happen as I would expect, which comforts me in my initial understanding. There are a a few exceptions listed here. Your last paragraph answers my question very clearly. Would you care to point out where exactly the APA specifies this? Thanks! Commented Sep 18, 2019 at 7:54
  • @Alexandre d'Entraigues under GP 2, answer edited to be more specific. Commented Sep 18, 2019 at 13:09
  • Ahh, yes, I had somehow missed that. I will validate your answer: even though I do not agree with the first part of the answer, you have in the second part provided a clear answer with a trustworthy source backing it up. Thank you! Commented Sep 18, 2019 at 16:12

The phrase "a big-data-based product" has a different meaning than "a big data-based product". The first phrase means "a product based on big data", while the second phrase means "a big product based on data". So in this case, the location of the hyphen reflects a difference in meaning.

The article Using Hyphens in Compound Adjectives provides a similar a example: "a heavy-metal detector" is a detector for heavy metals, whereas "a heavy metal detector" is a metal detector that is ... heavy.

The APA style guide gives the following example of a compound where the base word consists of more than one word: "non-achievement-oriented students".

  • On the first point, I am not sure I agree: the rules I have found mention specifically that adverb-adjective combinations where the adverb end in -ly need not be hyphenated, which seems to imply that adverbs not ending in -ly should be hyphenated: a below-average intelligence. Regarding the second point, I indeed wrote that the second sentence did not seem to have the meaning I wanted to give it, but I'd like to know if the first sentence is correct and where I can find some reference on that. Commented Jul 12, 2017 at 9:06
  • I have deleted the paragraph about adverbs and added a link to an article that provides a similar example where the location of the hyphen expresses a difference in meaning. By the way, in "below-average intelligence", "below-average" looks like a preposition-noun combination, rather than an adverb-adjective combination.
    – Tsundoku
    Commented Jul 12, 2017 at 9:26
  • Thanks for the link, though it does not exactly cover the whole "what to do if one of the parts of the compound adjective contains two words" matter. Regarding "below-average", you seem to be right; perhaps "well-mannered gentleman" would have been a better example. Commented Jul 12, 2017 at 9:30
  • @Alexandred'Entraigues A few years ago, I checked at least half a dozen style guides etc. to write some guidance for non-native speakers of English; it is hard to find anything that goes into this level of detail, i.e. rules for compound adjectives where one of the parts is already a compound.
    – Tsundoku
    Commented Jul 12, 2017 at 9:44

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