Fellow participant in the ritual cry — συνευαστήρ

Meaning

The Prayer calls on all the συνευαστῆρες of Bacchos (Prayer.34): those who join him in the Bacchic cry. The prefix adds participation together with someone, while the rest of the word identifies the vocal action. The supplied English spells out that action as crying euhoi. Keep this noun distinct from εὐαστήρ and from the different formation εὐαστής.