IPA: /ˌɑːrkɪˈdiːkənl/
KK: /ɑrˌkɪˈdiːkənl/
Relating to an archdeacon, who is a senior clergy member in certain branches of the Christian church.
The archidiaconal duties include overseeing the work of the deacons in the diocese.
Archidiaconal → It is formed from "archi-" (from Greek "archi", meaning chief or principal) and "diaconus" (from Latin, meaning deacon). The term refers to the chief deacon or a position related to the chief deacon in the church hierarchy.
Think of 'archi-' meaning chief and 'diaconus' referring to a deacon — this helps you remember that 'archidiaconal' relates to the chief deacon in a church.
No commonly confused words.