1125–75; Middle English co(u)nsile < Anglo-French cuncil(e), Old French concile < Late Latin concilium synod, church council (Latin: assembly), probably equivalent to Latin con- con- + -cil(āre), combining form of calāre to summon, convoke + -ium -ium; Middle English -s- by association with Anglo-French cunseil counsel

Council, counsel, and consul are not interchangeable. Council is a noun. Its most common sense is “an assembly of persons convened for deliberation or the like.” It is generally used with a singular verb. A member of such a group is a councilor. Counsel is both noun and verb. Its most common meaning as a noun is “advice given to another”: His counsel on domestic relations is sound. A person giving such advice is a counselor. In law, counsel means “legal adviser or advisers” and can be either singular or plural. As a verb, counsel means “to advise.” The noun consul refers to the representative of a government who guards the welfare of its citizens in a foreign country.