head word head word /hɛd wɜrd/

noun

1. (grammar) the word in a grammatical constituent that plays the same grammatical role as the whole constituent  ( head word , head )
   (grammar) the word in a grammatical constituent that plays the same grammatical role as the whole constituent
   
2. A content word that can be qualified by a modifier  ( head word , headword )
   a content word that can be qualified by a modifier