IPA: /ɪnˈædɪkwət/
KK: /ɪnˈædɪkwət/
Not enough to meet a need or requirement; lacking in quality or quantity.
The resources provided for the project were inadequate, leading to delays.
Inadequate → It is formed from "in-" (meaning not) and "adequatus" (from Latin, meaning equal or sufficient). The word "inadequate" means not sufficient or not equal to what is required.
Think of 'not' ('in-') being combined with 'sufficient' ('adequatus') to remember that inadequate means something is not enough.