- detentionnounChapter 1 →
A school punishment requiring a student to stay after hours or report to a supervised room, used here as the setting where the five main characters are gathered when the death occurs.
- appnounChapter 1 →
Short for application — here specifically the gossip-sharing mobile app called About That, which Simon runs to expose secrets about students at the school.
- anaphylactic shocknounChapter 1 →
A sudden, severe, life-threatening allergic reaction that causes the body to go into crisis; in this text it is the medical emergency that kills Simon.
- EpiPennounChapter 1 →
A brand-name auto-injector device that delivers a dose of epinephrine to stop a severe allergic reaction; Simon's EpiPen is missing when he needs it, which is central to the mystery.
- peanut allergynounChapter 1 →
A potentially fatal immune-system reaction triggered by eating or being exposed to peanuts; Simon's known peanut allergy is the mechanism of his death.
- gossip appnounChapter 1 →
A smartphone application used anonymously to spread rumours and private information about people; the one in this novel, About That, is what gives Simon his power over classmates.
- suspectnounChapter 2 →
A person whom police or investigators believe may be responsible for a crime; all four surviving students in detention become suspects in Simon's death.
- attorneynounChapter 2 →
A lawyer who represents a client in legal matters; the students' families hire attorneys to advise them during the police investigation.
- alibinounChapter 2 →
Evidence or a claim that a person was somewhere else when a crime occurred, making it impossible for them to be the one who committed it.
- media frenzyphraseChapter 6 →
An intense, chaotic burst of news coverage and public attention surrounding a dramatic event; the students face this after Simon's death turns into a high-profile murder investigation.
- manslaughternounChapter 6 →
The unlawful killing of a person without prior intent to murder; one of the possible charges the students fear being brought against them.
- probationnounChapter 8 →
A court-ordered period during which an offender must follow certain rules and check in with authorities instead of serving time in prison.
- burner phonenounChapter 8 →
A cheap, prepaid mobile phone bought anonymously and used temporarily so that calls and messages cannot be traced back to the owner.
- toxicology reportnounChapter 10 →
An official medical document that identifies drugs, poisons, or other substances found in a person's body, used here as part of the investigation into how Simon died.
- immunitynounChapter 14 →
A formal legal agreement in which a prosecutor promises not to charge someone with a crime in exchange for their cooperation or testimony.
- subpoenanounChapter 14 →
A legal order requiring a person to appear in court or hand over documents; receiving one means the law is formally demanding your participation.
- grand jurynounChapter 14 →
A group of citizens convened to review evidence and decide whether there is enough to formally charge someone with a crime and bring them to trial.
- depositionnounChapter 18 →
Formal sworn testimony given outside a courtroom, recorded by lawyers before a trial; witnesses must answer questions truthfully or risk perjury charges.
- perjurynounChapter 18 →
The crime of deliberately lying while under oath in a legal proceeding; a charge the students risk if they are caught being untruthful with investigators.
- premeditatedadjectiveChapter 22 →
Planned or thought out in advance before being carried out; used here to distinguish deliberate murder from an accidental or impulsive act.
One of Us Is LyingNovel by Karen M. McManus