U

disappointing

adjective

failing to fulfill one’s hopes or expectations: a disappointing movie; a disappointing marriage.

verb (used with object)

to fail to fulfill the expectations or wishes of: His gross ingratitude disappointed us.
to defeat the fulfillment of (hopes, plans, etc.); thwart; frustrate: to be disappointed in love.

verb (used without object)

to bring or cause disappointment.

adjective

failing to meet one’s expectations, hopes, desires, or standards

verb (tr)

to fail to meet the expectations, hopes, desires, or standards of; let down
to prevent the fulfilment of (a plan, intention, etc); frustrate; thwart

early 15c., “dispossess of appointed office,” from Middle French desappointer (14c.) “undo the appointment, remove from office,” from des- (see dis-) + appointer “appoint” (see appoint).

Modern sense of “to frustrate expectations” (late 15c.) is from secondary meaning of “fail to keep an appointment.” Related: Disappointed; disappointing.