Definite means clearly stated, certain, or having exact limits. When your teacher asks for a definite answer rather than “maybe” or “I think so,” she wants you to commit to something specific. When plans are definite, everyone knows exactly what's happening: “we're going to the park at 2:00 PM on Saturday” instead of “we might go to the park sometime.”

The word often appears when people want to remove doubt or vagueness. A doctor gives a definite diagnosis when she's certain what's wrong, based on clear evidence. A definite improvement means you can clearly see that something got better, with noticeable changes. Scientists look for definite proof before accepting a new theory.

When you define a word, you explain its exact meaning. When something is definite, it has clear edges and boundaries, too.

The opposite is indefinite, meaning uncertain or unclear. An indefinite wait could last minutes or months. Notice that people often say “definitely” when they mean “yes, absolutely” or “without question”: “Are you coming to my party?” “Definitely!”