IPA: /ɪˈpɪstələr/
KK: /ɪˈpɪstələr/
A person, usually a member of the clergy, who reads the epistle during a church service, particularly in Anglican traditions.
During the service, the epistoler read the passage from the New Testament.
Epistoler is derived from the word 'epistle' (from Old French *epistole*, meaning letter) combined with the suffix '-er' (meaning a person who). An epistoler is therefore a person who writes letters or epistles.
Think of someone who writes letters ('epistle') — the '-er' indicates that this person is doing the action of writing.