What term describes the failure to fulfill a legal requirement or duty, which indicates guilt of an offense?

The term that describes the failure to fulfill a legal requirement or duty, which indicates guilt of an offense, is best captured by "delinquent." This term often refers to individuals, especially minors, who commit acts that are in violation of the law or fail to comply with legal obligations.

In a legal context, "delinquent" illustrates a pattern of behavior that is not only unlawful but also reflects an individual's disregard for the rules set by society. When a person is labeled as delinquent, it signifies that they have engaged in conduct that merits intervention from the legal system, often leading to legal consequences.

The other terms provided have specific meanings that do not align as precisely with the definition of failing to fulfill a legal duty. A conviction refers to the legal judgment that someone is guilty of a crime, a plea represents a defendant’s formal response to criminal charges, and an offense denotes an act that violates the law. While they all relate to legal matters in some way, they do not encapsulate the concept of failure to fulfill legal obligations in the same manner as "delinquent."