associate pastor; curate
A Christian clerical title for a pastor who assists the senior pastor; common in Protestant contexts. Curate is the equivalent in Anglican/Episcopal settings.
He serves as the associate pastor of that church.
The curate delivered the sermon at the Sunday service.
主任牧師 is the senior or head pastor, in contrast to the assistant role of 副牧師.
Compound of 副 (vice-, assistant) and 牧師 (pastor, minister). 牧師 is a Meiji-era coined term for Christian clergy.