Which unit does not belong to the set?

1. lexicographer, dictionary-maker, publisher, editor, compiler;

2. diachronic dictionary, historical (linguistic) dictionary, etymological dictionary, dictionary of historicisms;

3. diacritical marks; frequency index (indices); entry; head-word, illustrative quotations;

4. vocabulary, dictionary, glossary, concordance, thesaurus, lexis, word-book;

5. unilingual dictionary, bilingual dictionary, translation dictionary, multilingial dictionary, polyglot dictionary;

6. phonetic dictionary, spelling dictionary, pronouncing dictionary, orphoepic dictionary;

7. reverse dictionary, pictorial dictionary, rhyming dictionary, back-to-front dictionary;

8. dictionary of collocations, phraseological dictionary, terminological dictionary, new words dictionary;

9. unabridged dictionary, general dictionary, word-frequency dictionary; dialectal dictionary.