When something is deemed inadequate, it is considered to be insufficient or not good enough for the task at hand. Synonyms for inadequate include insufficient, deficient, lacking, and wanting. Something that is subpar or below average can also be considered inadequate. In some cases, a person or thing may be described as unsatisfactory or unacceptable due to inadequacy. Other synonyms include inadequate, unsatisfying, meager, and low-quality. The opposite of inadequate is adequate, meaning sufficient or satisfactory. When searching for synonyms for inadequate, keep in mind the context in which the word is being used.