to call together / to summon / to convene / temple or monastery (used in place names in Inner Mongolia)
召
=
刀
+
口
:
Mnemonic symbol: an intercom to call everyone together. James II of England (zh) prepares a few mandarins (口) for everyone in the aorta's bathroom (ao4) by cutting them with a cleaver (刀). As he is finished he calls everyone together (召) over the intercom (召) to come over and fetch a piece.