Inadequate means not enough, or not good enough, for the purpose. Inadequate funding, an inadequate response, feel inadequate.
Applied to a thing it is a plain measure against a requirement. Applied to a person it is about feeling rather than fact: feeling inadequate is extremely common and correlates poorly with actually being so, which is worth knowing.
1adjectiveinadequateNot enough, or not good enough, for the purpose.
“The hospital's heating was inadequate, and patients shivered through the winter.”
inadequate is a quality.
From in- + adequate.
Etymology from Wiktionary, CC BY-SA