Picture a letter going out to a long list of people, all of whom have to come. Someone with the authority to do it has fixed a day and a hall, and on that day people travel in from everywhere and sit down in one room. That is the whole picture: not people deciding to meet, but people being called. Every use of convocation keeps some part of it — sometimes the meeting that results, sometimes the act of calling itself, sometimes the last day a university calls its students together, and once, in older writing, a sky full of eagles gathered as if summoned.
From the word’s history
The supplied source traces convocation through Middle English convocacioun and Old French from Latin convocatio, convocationem. The Latin noun is from the same family as voice and vocal, so the idea of calling sits inside the word rather than being added to it later.
本次證據裡的 Wiktionary 記載：convocation 經由中古英文 convocacioun 和古法文，來自拉丁文 convocatio／convocationem。那個拉丁字跟 voice、vocal、invoke 可以想成同一家人，核心都繞著「叫、發聲」。所以「把人叫到一起」不是後來加上去的意思，它本來就在字裡面。
Wiktionary, "convocation"
登入就可以看每一支怎麼連回核心畫面。