Dictionaries, Thesauri and Style Guides

It is important to have a good dictionary and thesaurus close to hand for writing, whether in digital or print format. If English is your second or third language, bilingual dictionaries are useful as well. Some of the websites offer multiple resources within one site.

Dictionaries help decode words, supply definitions and indicate correct spelling.

Different dictionaries serve different purposes, with varying levels of information and quality. Some of the most highly recommended monolingual dictionaries for English are:

Another resource that offers spelling tips, exercises, thesauri, an open dictionary, and a pronunciation assistance for dictionary entries is:

MacMillan Dictionary

OneLook is a metadictionary site that finds words even when you search on a partial spelling. The site uses a simple search box and provides an uncluttered interface.

OneLook Dictionary

Thesauri (singular: thesaurus) assist writers with varying words and phrases by providing synonyms and antonyms.

English-language thesauri come in two basic formats: a newer dictionary format, and Roget’s original structure. The former, as you might guess, has entries arranged alphabetically with synonyms and antonyms at each main entry (accessed via an index). The latter is essentially a set of semantic fields, subdivided by topic, organized within each topic by part of speech, all accessed by a very large index at the end.

Be careful with thesauri, if you are unsure of the denotation (reference) and connotation (its implications beyond its direct reference), use a thesaurus with other dictionaries.

NOTE: Avoid varying a term too much because readers need to track the ideas or concepts throughout the work. For example, if a paper references a particular dataset, a writer should use the term dataset throughout the work to ensure consistency. However, if one uses a word such as “good” or “strong” throughout a work, the variety in those descriptive words give the reader a more robust document to assess.

In addition to some of the previously mentioned resources, here are two more thesauri:

The Oxford Paperback (Online) Thesaurus

and, which is search only.

Usage Manuals

These guides contain information regarding grammar and word choice, particularly problematic expressions (e.g., “effect” vs. “affect”):