We present etytree (from etymology + family tree): a new on-line multilingual tool to extract and visualize etymological relationships between words from the English Wiktionary. A first version of etytree is available at http://tools.wmflabs.org/etytree/. With etytree users can search a word and interactively explore etymologically related words (ancestors, descendants, cognates) in many languages using a graphical interface. The data is synchronised with the English Wiktionary dump at every new release, and can be queried via SPARQL from a Virtuoso endpoint. Etytree is the first graphical etymology dictionary, which could be used to search specific etymological definitions as well as to discover new relations among words. Moreover, it can be effectively adopted by Wiktionary editors to identify inconsistencies or missing information in the data. Etytree is a valuable tool for all those users interested in specific etymological definitions as well as for discovering new relations among words. Moreover, it can be effectively adopted by Wiktionary editors to identify inconsistencies or missing information in the data.