guideword

A guideword is a term used in lexicography to describe the word or words printed at the top of a dictionary page that indicate the range of headwords contained on that page. In traditional print dictionaries, each page spread commonly shows two guidewords: on the left-hand page the first headword appearing there, and on the right-hand page the last headword on that page. Some editions place guidewords at the top of the page edges for double-page spreads. The primary function is navigational, helping readers judge whether a desired word is likely to be on a given page and to estimate its location before turning pages. This aids efficient browsing by reducing unnecessary page turning.

Guidewords are distinct from the entries themselves and from general page headers that indicate chapters or sections. In modern online dictionaries or glossaries, explicit guideword headers may be omitted, though the underlying navigational principle remains in search and index features. The concept also appears in indexing and encyclopedias, where range indicators show the first and last term on a page or section. The term guideword is sometimes referred to as a lead word or headword guide.

Example: a page containing headwords from abate to abbreviate may display "abate" (left) and "abbreviate" (right) as guidewords.