unanticipated

Unanticipated is an adjective describing something that is not anticipated, foreseen, or expected. It refers to events, outcomes, or conditions that occur without prior prediction and often require a response or adjustment. In formal writing, it is commonly used in contexts such as risk assessment, planning, and analysis to indicate surprises that were not accounted for in advance. Examples include unanticipated costs, unanticipated delays, and unanticipated obstacles.

Etymology and usage notes: the word is formed from the prefix un- attached to anticipated. Anticipated comes from the Latin anticipatus, via the development of anticipare in proto- and early modern English. Unanticipated tends to appear in more formal or technical contexts than everyday synonyms like unexpected or unforeseen, and it can convey a sense of deviation from planned expectations rather than mere surprise.

Nuance and related terms: while all three terms—unanticipated, unforeseen, and unexpected—convey surprise, unanticipated emphasizes the lack of prior expectation or planning, whereas unforeseen also stresses that something was not foreseen, and unexpected stresses surprise regardless of whether it was anticipated. Unanticipated can be used similarly to unplanned or unpremeditated in some contexts, but it more specifically signals deviation from beforehand expectations. It is often paired with nouns describing events, costs, or consequences.

See also: anticipate, anticipated, unexpected, unforeseen, unforeseen consequences, risk management.