The following terms have traditional meanings for the Anglican Church, and possibly beyond:
A churchman is in principle a member of a church congregation, in practice someone in holy orders.
A clergyman can be assumed to be in holy orders. The clergy is a term applied widely across many religions, while clergyman has connotations at least of Protestantism: while a Catholic, Anglo_Catholic or Orthodox Christian. A minister might belong to any Protestant church (not Catholic).
A pastor is the senior local minister (or priest), for example in a parish.
A preacher, from the Anglican point of view, is a colloquialism used for a clergyman rather than a formal title — or it may be someone who preaches.
A canon is a priest who is specifically attached to a cathedral and has some responsibility its organisation.
Many clergymen say in despair that their sermons seem to fall upon deaf ears; that people are able to compartmentalize their lives so that prejudice, hatred and selfishness remain unaffected by messages from the pulpit.
This deaf-ears argument was rejected right away—two-thirds of the ministers (68 per cent) agreed that "Clergymen have great potential to influence the political and social beliefs of their parishioners." And this belief in the power of the pulpit was not related to the Doctrine Index.
Indeed, the clergymen recognize this: 94 per cent of the liberal ministers thought their own theological views generally encouraged their participation in social-action activities, but only 39 per cent of the most conservative clergy thought so.