To underfund means to provide less money than something actually needs to work properly. When a program, project, or organization is underfunded, it doesn't have enough resources to do its job well.

Imagine a school library that needs $10,000 to buy new books, repair old ones, and keep everything running smoothly, but only receives $4,000. That library is underfunded. It might have to choose between fixing broken chairs or buying new books, when it really needs to do both. An underfunded animal shelter might not have enough money for medical care, food, and building repairs, leading to difficult choices.

Being underfunded creates real problems. An underfunded space program might have to cancel important missions. An underfunded youth sports league might not afford enough equipment for all the kids who want to play. When something is chronically underfunded, year after year, the problems pile up: equipment breaks and can't be replaced, talented people leave for better opportunities elsewhere, and the quality of work suffers.

The opposite is overfunded, though that's less common. Most organizations would rather have too much money than too little. When politicians or leaders debate budgets, they often argue about whether programs are underfunded or whether they're simply using their money poorly.