Inadequate means not enough or not good enough for what's needed. When something is inadequate, it falls short of what the situation requires.

If you show up to a snowstorm wearing just a light jacket, your clothing is inadequate for the weather: you need something warmer. If a bridge is built with materials too weak to support heavy traffic, those materials are inadequate for the job. When a student gives a one-sentence answer to an essay question, that response is inadequate because the question demands much more.

The word often appears when measuring something against a standard or requirement. A flashlight with dying batteries might provide inadequate light for reading. A small bandage would be inadequate for covering a large scrape. Three hours of study might be inadequate preparation for a major exam.

People sometimes feel inadequate when they doubt their own abilities, even though feelings don't always match reality. Someone might feel inadequate at math despite actually doing fine, or feel inadequate as a friend when they're being a perfectly good one. The feeling of inadequacy is that nagging sense that you're somehow not measuring up.

The opposite of inadequate is adequate (enough, but just barely) or more than adequate (plenty good enough).