"Draw out your vowels" is a common direction given to singers. It means to extend the length of your vowels while singing. Some synonyms for this direction could include elongate your vowels, sustain your vowels, prolong your vowels, or stretch out your vowels. It's important for singers to draw out their vowels in order to improve their vocal technique and create a more pleasing sound. By lengthening the duration of each vowel sound, singers can improve their pitch accuracy and add depth to their vocal performance. Practicing this technique can also help with breath control and overall vocal endurance.