What term refers to a brief or unexpected meeting?

The term "encounter" accurately describes a brief or unexpected meeting between individuals. In this context, an encounter often implies spontaneity and can occur in various situations, whether social or professional. This word encapsulates the notion of two parties meeting without prior arrangement or anticipation, which aligns closely with the concept of an unexpected interaction.

While "engagement," "meeting," and "association" can imply different types of interactions, they generally lack the specificity of being brief or unexpected. An engagement typically suggests a more formal or planned interaction, while a meeting usually refers to a scheduled gathering of multiple people. An association denotes a more lasting relationship or connection between parties. Thus, "encounter" best fits the definition of a short, chance meeting.