Συνείδησις = Syneidesis is a two parts word, συν + είδησις = syn + eidesis. The "συν/syn" implies the collective, the coming together, it's the same συν that means plus in math. Είδησις/eidesis means news, as we hear the news on tv for example, meaning that we hear already done and therefore past events being announced and broadcasted in the news. The word syneidesis implies that now we ourselves have knowledge to the already happened events.