noun Date: 1859 a word that is a key: as, a word exemplifying the meaning or value of a letter or symbol, a significant word from a title or document used especially as an index to content
KEY WORD
Meaning of KEY WORD in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012