Learner's definition of SUMMON
to order (someone) to come to a place
to order (someone) to appear in a court of law
— often used as (be) summoned
to ask for (someone or something) to come
to send or call for (someone or something)
She summoned a doctor.
The boy summoned help.
to get (the courage, energy, strength, etc., that you need to do something) by making a special effort
— often + up
to ask or order a group of people to come together for (a meeting)
summon up (something)
to bring (a memory, feeling, image, etc.) into the mind
see also summon 3 (above)