gab·bai 
(gä-bī, gäbī′, gə-bī)
(gä-bī, gäbī′, gə-bī)n. gab·ba·im (gä-bä-ēm, gä-bīĭm) or gab·bais
A person who assists in the running of a synagogue or its religious services, especially the reading of the Torah.
[Medieval Hebrew gabbay, synagogue treasurer, gabbai, from Mishnaic Hebrew, tax collector, local official, from gābā, to collect, from Aramaic gəbā, gəbi, to collect; see gbʾ in the Appendix of Semitic roots.]