synagogue

From Middle English synagoge, borrowed via Old French synagoge and Latin synagōga, from Ancient Greek σῠνᾰγωγή (sŭnăgōgḗ), meaning 'assembly, gathering.' That Greek noun comes from συνάγω (sunágō, 'to gather together'), itself built from σῠ́ν (sŭ́n, 'with, together') and ᾰ̓́γω (ắgō, 'to lead').

The word began as a plain Greek term for any assembly or gathering, formed from 'leading together,' before it narrowed in Latin and later English to mean a specific place of Jewish worship.

By surface analysis it splits into syn- and -agogue, the same -agogue piece that shows up in words like 'pedagogue' — someone who 'leads' the young.