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Attributions

TailSpin is built on work that other people did and gave away. This page says whose, and under what terms. Some of it we are required to say. All of it we would say anyway.

Word definitions

The definitions shown when you tap a word come from three open dictionary projects. Every definition in TailSpin carries the name of the source it came from, shown on the definition card itself. That is a condition of using them, and it is also just accurate: these are other people's words, not ours.

Wiktionary

Most definitions in TailSpin come from English Wiktionary, extracted using the wiktextract project and distributed by kaikki.org. We use the English dump of 6 September 2026.

Wiktionary is dual-licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence (CC BY-SA 4.0) and the GNU Free Documentation License.

ShareAlike means that if you take the definition text out of TailSpin and build on it, what you build has to carry the same licence. Reading a definition in the app, or sharing your result, does not trigger that. Copying the definitions out to make something else does.

Princeton WordNet 3.0

Where Wiktionary has no entry, we fall back to Princeton WordNet 3.0, a lexical database built at Princeton University.

Used under the WordNet 3.0 licence (Princeton University, 2006), which permits use, copying, modification and distribution for any purpose provided the copyright notice and this paragraph travel with it. WordNet is provided by Princeton "as is" and without warranty.

Open English WordNet 2023

Where neither of the above has an entry, we use Open English WordNet, 2023 edition, the community-maintained successor to Princeton's WordNet.

Used under the Creative Commons Attribution 4.0 International licence (CC BY 4.0).

A note on the definitions themselves

TailSpin shows the source's first sense for a word, and the source's idea of which sense comes first is not always the one you had in mind. That is why the card says "+N more senses" when there are others. We have not rewritten, edited or improved any of these definitions, which is deliberate: they are the sources' work, and presenting an altered version under their name would be worse than presenting a sometimes-surprising one.

Definitions are there because they are interesting. They are not the rule for what counts as a word in TailSpin — that is the word list below.

The word list

Which words TailSpin accepts is decided by a list assembled from three sources, then filtered.

  • SCOWL (Spell Checker Oriented Word Lists), compiled by Kevin Atkinson, release 2020.12.07, used under its own permissive licence with its copyright notice retained. wordlist.aspell.net

    SCOWL's notice, verbatim:

    Copyright 2000-2018 by Kevin Atkinson

    Permission to use, copy, modify, distribute and sell these word lists, the associated scripts, the output created from the scripts, and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appears in all copies and that both that copyright notice and this permission notice appear in supporting documentation. Kevin Atkinson makes no representations about the suitability of this array for any purpose. It is provided "as is" without express or implied warranty.

    SCOWL incorporates word lists from other sources under the notices in its Copyright file, which we keep with the lists: dictionary/sources/scowl/Copyright.

  • The Moby Project word lists, placed in the public domain by Grady Ward.

  • WordNet lemma lists, from Princeton WordNet, under the licence described above.

Word frequencies, which we use to decide how obscure a word is, are computed with the wordfreq library by Robyn Speer.

We also use the List of Dirty, Naughty, Obscene and Otherwise Bad Words (LDNOOBW), released under CC0, as one input to the filtering. It is listed here for completeness rather than obligation.

The list is ours in its assembly and filtering, not in its contents. No one owns the English language.

Avatar emblems

The emblems a player can choose for their avatar are drawn from game-icons.net, used under the Creative Commons Attribution 3.0 Unported licence (CC BY 3.0). We recolour them to match a player's avatar and scale them to fit; the shapes are the artists' work.

The emblems in TailSpin are by:

  • Lorc
  • Delapouite
  • Skoll
  • Caro Asercion

Each artist's work, and their own pages, are listed at game-icons.net.

Typefaces

The Open Font License lets us use, embed and redistribute these fonts freely, including inside the images TailSpin generates for link previews, provided we do not sell the fonts themselves and provided this notice exists. It does.

Software

TailSpin is built with a large amount of open-source software, including React Native, Expo, React, PostgreSQL, Supabase, Next.js and many smaller libraries, each under its own licence. We are not going to pretend we could have built this without them.

If you maintain something we depend on and would like specific acknowledgement here, email support@tailspin.gg and we will add it.

Corrections

If you think something on this page is wrong, incomplete, or misattributes your work, tell us at support@tailspin.gg. We will fix it.

Last updated: October 9, 2026. Definitions current as of dictionary version v2026-09-07-001.