A word or term that is listed as an entry in a dictionary, glossary, or index, usually in bold or larger type, and is followed by its definition or explanation.
In the dictionary, each headword is followed by its pronunciation and meaning.
A word or phrase that is the main topic or subject of a section in a reference work, such as an encyclopedia or thesaurus.
The headword 'climate change' in the encyclopedia includes various articles and references.
In syntax, the word within a phrase that determines the phrase’s grammatical type and can often stand alone as its core.
In the noun phrase "bright yellow flowers", the headword is "flowers".