plead - to make, deliver, or file any pleading; to conduct the pleadings in a cause. To interpose any pleading in a civil action. More particularly, to deliver in a formal manner the defendant's answer to the plaintiff's declaration, complaint or to the indictment, as the case may be., plead - to raise or prosecute a suit or action, to go to law, to litigate, pleadings - the formal allegations by the parties to a lawsuit of their respective claims and defences, with the intended purpose being to provide notice of what is to be expected at trial