The main difference between Vicar and Reverend is that the Vicar is a type of priest and Reverend is a Christian religious title
A vicar (; Latin: vicarius) is a representative, deputy or substitute; anyone acting “in the person of” or agent for a superior (compare “vicarious” in the sense of “at second hand”). Linguistically, vicar is cognate with the English prefix “vice”, similarly meaning “deputy”. The title appears in a number of Christian ecclesiastical contexts, but also as an administrative title, or title modifier, in the Roman Empire. In addition, in the Holy Roman Empire a local representative of the emperor, perhaps an archduke, might be styled “vicar”.
The Reverend is an honorific style most often placed before the names of Christian clergy and ministers. There are sometimes differences in the way the style is used in different countries and church traditions. The Reverend is correctly called a style but is often and in some dictionaries called a title, form of address or title of respect. The style is also sometimes used by leaders in non-Christian religions such as Judaism and Buddhism.
The term is an anglicisation of the Latin reverendus, the style originally used in Latin documents in medieval Europe. It is the gerundive or future passive participle of the verb revereri (“to respect; to revere”), meaning “[one who is] to be revered/must be respected”. The Reverend is therefore equivalent to The Honourable or The Venerable. It is paired with a modifier or noun for some offices in some religious traditions: Anglican archbishops and most Roman Catholic bishops are usually styled The Most Reverend (reverendissimus); other Anglican bishops and some Roman Catholic bishops are styled The Right Reverend; some Reformed churches have used The Reverend Mister as a style for their clergy.
With Christian clergy, the forms His Reverence and Her Reverence is also sometimes used, along with its parallel in direct address, Your Reverence. The abbreviation HR is sometimes used.
In the Church of England, the priest of a parish, receiving a salary or stipend but not tithes.
In the Roman Catholic and some other churches, a cleric acting as local representative of a higher ranking member of the clergy.
A person acting on behalf of, or representing, another person.
worthy of reverence or respect
a member of the Christian clergy
(in the Church of England) an incumbent of a parish where tithes formerly passed to a chapter or religious house or layperson.
(in other Anglican Churches) a member of the clergy deputizing for another.
(in the Roman Catholic Church) a representative or deputy of a bishop.
(in the US Episcopal Church) a member of the clergy in charge of a chapel.
a cleric or choir member appointed to sing certain parts of a cathedral service.
used as a title or form of address to members of the clergy
“the Reverend Pat Tilly”
a member of the clergy
“a retired reverend”