Related Clues:

• Kind of booster
• Concern for self
• Inner self
• 'I strain'
• Self-importance
• 'I trouble?'
• Megalomaniac's problem
• Trip starter?
• Id counterpart
• Type of maniac
• Potential Guinness World Records entry
• Accounting entry
• Swellheadedness
• A smartypants may have a big one
• It might get in the way of an apology