How can I select data with one query?
I don't know mysql syntax, but it seems like the following would give you the same results.

SELECT b.id, b.language, b.word, b.state, b.domein, b.characteristic, a.lang1 
FROM xwrh9_betty_dictionary_ids a 
LEFT JOIN xwrh9_betty_dictionary_words b ON b.id=a.lang1 OR b.id=a.lang2
WHERE b.id&lt;&gt;19
GROUP BY b.id;