headword

[hed-wurd] /ˈhɛdˌwɜrd/
noun
1.
a word, phrase, or the like, appearing as the heading of a chapter, dictionary or encyclopedia entry, etc.
2.
catchword (def 2).
3.
head (def 26).
Origin
1815-25; head + word
British Dictionary definitions for headword

headword

/ˈhɛdˌwɜːd/
noun
1.
a key word placed at the beginning of a line, paragraph, etc, as in a dictionary entry