Main Entry:

let·down

Pronunciation:

\ˈlet-ˌdau̇n\

Function:

noun

Date:

1768

1 a: discouragement, disappointment <his latest novel is a letdown> b: a slackening of effort : relaxation2: the descent of an aircraft or spacecraft to the point at which a landing approach is begun3: a physiological response of a lactating mammal to suckling and allied stimuli whereby previously secreted milk from the acini is expelled into ducts and drawn through the nipple