The Latin root of adequate means "equal to," so inadequate refers to things that aren't equal to what is expected or needed.

What is the cause of inadequacy?

Most often, feelings of inadequacy are rooted in childhood experiences, like having had overly critical parents, cruel peers, shaming authority figures, or, perhaps, having not had opportunities to engage in positive, challenging experiences that help children gain feelings of competence and adequacy.

What does it mean when a person is inadequate?

If someone has feelings of inadequacy, they feel that they do not have the qualities and abilities necessary to do something or to cope with life in general. ... his deep-seated sense of inadequacy. Synonyms: incompetence, inability, deficiency, incapacity More Synonyms of inadequacy.