Q: Is answer a reply to a question? ¶
A: Yes.
Q: Was answer originally a solemn assertion in opposition to someone or something? ¶
A: Yes, and thus generally any counter-statement or defense, a reply to a question or response, or objection, or a correct solution of a problem.
Q: Is answer the first pleading by a defendant? ¶
A: Yes, and usually filed and served upon the plaintiff within a certain strict time limit after a civil complaint or criminal information or indictment has been served upon the defendant.