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

What do you mean by sub standard?

: deviating from or falling short of a standard or norm: such as. a : of a quality lower than that prescribed by law substandard housing. b : conforming to a pattern of linguistic usage existing within a speech community but not that of the prestige group in that community.

What type of word is disappointingly?

Disappointingly is an adverb - Word Type.