Possible Clues:

• Slurred speech?
• Jack-o'-lantern feature
• Linguistic device sound on reflection: large one included
• Omission of a syllable
• Omission of a vowel in pronunciation
• '10 lines, in a short form (7)'
• Omitting pieces in speech – TV drops one initially, and a couple more later
• Omission of a sound in speech
• Feature of op'nin' and hap'nin'
• She agreed to Acton in sibling solidartity