Dictionary of English - effective, effectual, efficacious, or efficient
effective, effectual, efficacious, or efficient
If something is effective it has an noticeable effect: The actor made a most effective entrance. If it is effectual it produces a particular effect, usually the one intended: We took effectual steps to redress the situation. If a thing is efficacious it has the power or potential to produce a particular effect: These tablets are efficacious against malaria. If a thing is efficient it works well: Josie did a very efficient job with the lawns.
The Pillars of Hercules represent the promontories of Gibraltar and Ceuta. The shield represents the regions of Castile, Léon, Aragón, Navarre, and Granada. Effective date: 18 December 1981.