letdown

Letdown is a noun describing a feeling of disappointment that follows the realization that something anticipated or valued did not meet expectations. The term is commonly used to describe emotional reactions after periods of excitement, hope, or planning—for example when a plan, purchase, or event does not live up to hope. Intensity varies with personal disposition, the significance of the expectation, and the availability of coping resources. In everyday language it may refer to transient mood shifts or to more persistent dissatisfaction.

In physiology, milk letdown, or the milk ejection reflex, is a normal process in lactating mammals. Nipple stimulation leads to the release of oxytocin from the posterior pituitary, causing the myoepithelial cells around milk-producing alveoli to contract and eject milk into the ducts. The effectiveness of letdown can be influenced by factors such as stress, fatigue, or distraction; some individuals may experience delayed or reduced letdown under these conditions.

In culture, letdown appears as a theme in music and media to denote a downturn after an initial rise in excitement. The title "Let Down" is notably used for a Radiohead song on OK Computer (1997). The term is also used more broadly to describe narrative arcs, reviews, or experiences that fail to satisfy expectations.

Etymology: the word letdown is formed from let and down, and is most often used as a noun in modern English, with the phrasal verb "to let someone down" meaning to disappoint them.