Missing dream meaning is explained below using 3 different sources. Each interpretation is shown with its source.

Interpretation 1 — James R. Lewis and Evelyn Dorothy Oliver

A missing article, such as a set of keys, denotes a sense of being out of control.

A missed plane, bus, train, appointment, or time commitment can symbolize a missed opportunity, and the frustration of being behind and unorganized is also suggested. (See also Loss of Something).

Source: Dream Symbols in The Dream Encyclopedia Author: James R. Lewis and Evelyn Dorothy Oliver

Interpretation 2 — myjellybean

A missing article in a dream, like a piece of clothing or textbook, suggests you are feeling out of control in some aspect of your life.
Source: My Dream Interpretation Author: myjellybean

Interpretation 3 — Margaret Hamilton

See “lost”
Source: Dream Dictionary Unlimited Author: Margaret Hamilton