1. to call upon or request to appear, especially officially or formally
2. to call forth or bring about through effort or will
3. to call to mind or recall

Examples

• The judge summoned the witness to testify.
• She was summoned to the principal’s office.
• He summoned all his courage before the big presentation.
• The defendant was summoned to appear in court next week.
• She tried to summon happy memories from her childhood.
• The captain summoned his crew to the deck.
• I need to summon the strength to finish this marathon.