EtymOnline is an excellent resource for online etymology searches. If, however, I am looking for lists of words sharing a given Latin, Greek or other root (which I call "reverse etymology"), I do not know which tool I could use. Do you know any?

The only thing I could think of is, if I had access to an offline etymology dictionary, I could then perform a full-text search into its content.

  • 2
    I'm voting to close this question as off-topic because it's a request for resources, and is surely better on meta. Oct 31, 2019 at 13:23

7 Answers 7


This can be achieved with a touch of Google-fu.

We want to limit our Google search to search only the site, http://www.etymonline.com/.

From reading the url structure of each result, we notice that definitions all contain ?term=, so can we refine the search with these bits of info:

site:etymonline.com inurl:term

Then, we add a space and the term we are looking for; if it appears in the text describing a word's etymology, we have a hit.

For example, we'd type the following if we wanted to search for phagos:

site:etymonline.com inurl:term phagos

Search results for "phagos"

We are a touch limited in that we must rely on the definitions containing that particular variant. For example, the above search returns 5 hits; however, a search for phagous returns 13 hits despite phagos and phagous sharing a common root.

Hope that helps!

EDIT: I've further played with this and noticed that occasionally it returns search pages which don't really add much.

These can be filtered out as they all contain the expression ?search=, so we can use:

site:etymonline.com inurl:term -inurl:search phagos

For anyone interested in understanding how that works, prepending a - negates the statement so -inurl:search evaluates to AND url does not contain "search".

  • That's a great approach. I just tried it with hydro and phobia and it worked very well!
    – b.roth
    Apr 7, 2011 at 15:19
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    This answer is last modified 9 years ago, very obsolete. The way "etymo online" URL works is now totally different. "inurl:term" is no longer neccesary it appears at all, it works very well without it, in any case you should use "inurl:word" since the links no longer say "term". It's unnecesary to use "-inurl:search" it appears. So, if you want to do this today, instead of this answer, you just google search "site:etymonline.com stop" and it will give you stoplight, stopcock, stopper, as results, very easily. Mar 24, 2020 at 0:32

Wiktionary maintains descendant lists, but they are far from complete. See e.g.:


Not online, but I picked up a second-hand copy of Pokorný's Indo-European Dictionary some years ago, and I often refer to it for this. I'm sure that scholarship has moved on since, though.

  • +1 for Pokorny! It is also available online on a website by the university of Leiden. It uses a phonetic rendering in Latin letters and characters whose name I forgot and that I can't properly read—or at least as they are displayed in my browser. ieed.nl/%5Cindex2.html It also has Frisk's Greek etymological dictionary! And here is a link to the list of PIE roots in Pokorny: homepage.ntlworld.com/richard.wordingham/pok/pok_index.htm Apr 8, 2011 at 4:45
  • P.S. Are you sure we need the accent on the y? Wikipedia doesn't have it, nor does Leiden. en.wikipedia.org/wiki/Julius_Pokorny Apr 8, 2011 at 4:48
  • Thanks for the Leiden link: I didn't know that was all available. As for Pokorný - it looks as if he dropped the accent - it exists on the name in Czech (See en.wikipedia.org/wiki/Pokorn%C3%BD). But I wonder where I got it from then?
    – Colin Fine
    Apr 8, 2011 at 13:48
  • Yeah he must have dropped it then, no other explanation I can think of. I see I forgot to upvote you in my haste to add an extra comment, how silly. Here it is. Apr 8, 2011 at 14:07
  • I was sure I must have got the "ý" from somewhere, but I've been to check the printed copy and it has "y". I never even questioned the "ý" when I wrote the comment.
    – Colin Fine
    Apr 11, 2011 at 11:05

The American Heritage Dictionary (used to be online, no more) had great etymology links back to the root of a word, which then had a link to all the words derived from the root. (so you could go backward and forwards in time).

Those old pages are available through the 'wayback machine' at


AHD (at that archive site) also has accompanying articles for Indo-European and Semitic roots, and lists of those roots which then link forward to derivatives:


Seems to be slow, but likely to be exactly what you want.

(A comment points out that the dictionary is still online, but it just doesn't offer the same list of IE roots or clickable etymology.)



As above, currently the roots are hotlines as well. Basically, you can search on a root word or particle and it shows all of the modern words derived from that root. Try searching for *per- in the search box.

  • Also, just going to that root will give you links: etymonline.com/word*per- gives even more than with the 'crossreference'
    – Mitch
    Oct 31, 2019 at 13:30
  • When I replace "*ad-" for something else, and it says "Error 404 (Not Found)" Mar 24, 2020 at 0:20

This misses many hits, but still gives a lot of results: METHOD 1:

1) Replace the word "still" for the word you want in the following link:


2) to filter bad results, do ctrl+f "still" (and variants that you suspect to match), those results will give you lots of words that are descendants.

METHOD 2: same as method 1, only to explain what the weird link means: 1) go to the "still" page on wiktionary Should get you here:


2)Click "what links here" (probably in the left side bar) Should get you here:


3) Click "500" to try to see all the results in the page.

4) do step "2" of METHOD 1.


There is a useful resource out there https://www.rabbitique.com that can help achieve just that. It is also multilingual, so you can search words in any language and then it finds the root and cross-lingual relatives.

  • -1. This doesn't work at all. I tried this with word roots like onomy and ation but it gave zero results. I tried using a whole word like astronomy but it only gave cognates containing the full word, rather than a list of words sharing one of the roots - I'd be expecting astrology and asterix (amongst others) for the first root, and gastronomy (etc) for the second. Mar 4, 2021 at 21:28

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