head·word, entry word

head·word (hĕd'wûrd')
n.

1. A word, phrase, or name, usually set in boldface or other distinctive type, that serves as the heading for an entry in a dictionary, encyclopedia, or similar reference work. Also called entry word.

The noun entry word has one meaning:

Meaning #1: the form of a word that heads a lexical entry and is alphabetized in a dictionary
Synonyms: citation form, main entry word

head・word n. - 標題字

日本語 (Japanese)（辞書などの）見出し語; 【文法】主要語 ((修飾を受ける語)).