To call upon or request the presence of someone, especially with authority or urgency.
From Old French somondre, from Latin summonēre meaning 'to remind secretly,' compound of sub- 'under' and monēre 'to warn.' Legal sense developed in medieval courts.
The word retains its ancient sense of authority and compulsion - you can't casually summon someone; there's always an implicit power dynamic that makes it stronger than simply 'call' or 'invite.'
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