Ectasis

noun

1. In anc. orthoëpy and prosody: The pronunciation of a vowel as long.
2. The lengthening or protraction of a vowel usually short. See diastole.
3. In ancient rhetoric: The use of a long vowel or syllable in a part of a clause or sentence where it will produce a special rhythmical effect.
4. The use of a form of a word longer than that commonly employed. This is generally called paragoge.
5. The lengthening of a syllable from short to long.