A distinguishing feature of Etymologeek.com is that we use etymology trees (directed graphs) to show the etymological history and relationships of each word.
Moreover, we try to show extensive information and descendants of our words, which is reinforced by filtering in order to make this data more interesting.
The etymology data is licensed under the CC BY-SA license. We aim to actively encourage people to use etymological data in other projects and we are willing to help them in doing so!
Our data is primarily derived from Wiktionary, the free multilingual dictionary, although we have made changes to the Wiktionary data by recombining it from different sources, performing extensive data filtering and making corrections and modifications where we were able to find mistakes or things to improve. We draw inspiration from and use the tool called Etytree by Ester Pantaleo for etymological data extraction.
We do not. Our data is largely automatically derived from free sources, and heavy automatic recombinatory operations are performed. We cannot guarantee the quality of the original data source, the accuracy of our filtering operations and our ability to spot and correct mistakes and inaccuracies as appropriate.
That said, we are actively working to constantly improve data accuracy. Some of our data is checked by humans and carries a mark showing that.
However, ultimately, all the data is prone to inaccuracies and we take no responsibility for your use thereof (sorry). At this point, we think etymology.com may be good as the first source of etymology information but not as the final source of it.