Reference, Dictionaries & Thesauri
OneLook, Wiktionary, Apple Dictionary, Merriam-Webster — what's that word?
The "what's that word" tool. Almost every writer eventually wants a reverse dictionary ("a word meaning X"), a slang dictionary, or a real OED. Most of the best are free and web. For rhyme / meter see writing-poetry-lyrics.
Reverse / contextual lookup
- ★ ★ OneLook — free; ★ ★ "a word meaning X" reverse dictionary, plus pattern search ("words like cl???er"), thesaurus, definitions across multiple sources. Indispensable for stuck-on-a-word moments.
- Reverse Dictionary (Wordsmyth, Lexico) — free; alternatives.
Built-in dictionaries
- ★ Apple Dictionary — free; macOS / iOS; built-in; New Oxford American + Oxford Thesaurus + Wikipedia; right-click any word.
- Microsoft Word Smart Lookup — free; built into Word.
- Google Define — free; type "define X" in Google.
- Mac / iOS Press-and-hold dictionary — free; built-in; the most-used dictionary in the world by accident.
Online dictionaries
- ★ Wiktionary — free; ★ the open-licensed dictionary; etymologies + multiple languages + slang; surprisingly good.
- Merriam-Webster (online) — free + paid; the US dictionary of record.
- Oxford English Dictionary (OED) — paid; institutional access common; ★ for historical / fiction set in the past — the OED's earliest-citation tool is unmatched.
- Cambridge Dictionary / Collins — free; UK-flavoured.
- Etymonline (Online Etymology Dictionary) — free; etymology focus.
- Urban Dictionary — free; slang; user-submitted; flag for accuracy + tone.
Thesauri
- Power Thesaurus — free + paid; crowdsourced; surprisingly comprehensive.
- Merriam-Webster Thesaurus — free.
- Thesaurus.com — free; older; ad-heavy.
- Visual Thesaurus — paid + free trial; visualizes synonym graphs.
- WordHippo — free; sentence-context examples.
Specialty dictionaries
- DSLs (Dictionary of the Scots Language) — free; for historical fiction.
- Greens Dictionary of Slang — paid + free; comprehensive English slang history; the standard for fiction set in any era.
- The Phrase Finder — free; idiom origins.
- A Dictionary of British Sign Language — free.
- Subject-specific dictionaries (legal / medical / nautical / military) — varied paid + free.
Idiom / collocation
- Just the Word — free; collocation search ("verbs that go with 'opportunity'").
- Linguee — free; bilingual collocations; great for translation. See writing-translation-cat-tools.
- Forvo — free; pronunciation by native speakers.
- YouGlish — free; how a word is pronounced in YouTube clips.
Style guides (book-shape reference)
- Chicago Manual of Style (CMOS) — paid online; the US trade-pub bible.
- AP Stylebook — paid; journalism standard.
- Garner's Modern English Usage — paid; opinionated usage reference.
- The Elements of Style (Strunk & White) — free (out of copyright); short + opinionated; controversial — beloved + criticized in equal measure.
- Microsoft Writing Style Guide — free online; modern, inclusive, tech-flavoured.
- Diversity Style Guide — free online; sensitivity-focused reference.
Quote / citation reference (separate)
- See edu-research-citations-zotero for academic citation tools.
Local / offline
- Apple Dictionary downloaded packs — free; multi-language offline.
- GoldenDict — GPL; free OSS; loads StarDict / DSL / Lingvo / etc. dictionary files; great for plane / no-WiFi work.
Pick this if…
- Reverse dictionary "word meaning X": OneLook.
- Built-in, fast: Apple Dictionary or Word Smart Lookup.
- Open / multi-language: Wiktionary.
- Etymology / historical fiction: Etymonline + OED.
- Slang: Greens Dictionary of Slang or Urban Dictionary (carefully).
- Style guide for trade pub: Chicago Manual of Style.
- Style guide for tech writing: Microsoft Writing Style Guide (free).
- Offline: GoldenDict + downloaded dictionaries.