missing

Missing is an adjective describing something that is not present, not found, or not accounted for. It can also be the present participle form of the verb miss, which has senses such as fail to hit, fail to attend, or fail to notice. The term is widely used in everyday language and in many specialized fields.

In reference to people, a missing person is someone whose location or safety is not known and who becomes the subject of searches and investigations by authorities. Missing-person cases vary in urgency and scope, but they commonly involve public alerts, coordination with families, and cross-jurisdictional cooperation.

In data and statistics, missing data denotes gaps where observations are not recorded. Reasons include nonresponse, data entry errors, or technical failures. Analysts distinguish missingness mechanisms—often described as missing completely at random, missing at random, or missing not at random—and employ methods such as deletion, imputation, or model-based approaches to address them.

In databases and information systems, missing values are frequently represented as NULLs, which can complicate queries and analyses. Data quality practices aim to minimize missingness, and validation rules or automated checks help ensure more complete datasets.

In inventory, archiving, or recordkeeping, items, documents, or entries may be missing, triggering audits, reconciliations, or updates to catalogs and inventories. The term also appears in everyday language to express absence or incompleteness, as in describing “a missing piece” of a puzzle or argument.