noncommittal
Not clearly saying yes or no about something.
Noncommittal means deliberately avoiding making a clear decision, giving a definite answer, or taking a firm position on something. When someone is being noncommittal, they're keeping their options open rather than committing to one choice.
You see this all the time in everyday situations. When your friend asks if you want to go to the movies this weekend and you say “maybe” or “we'll see,” you're being noncommittal. You're not saying yes, but you're not saying no either. Teachers sometimes give noncommittal responses when students ask what will be on the test: “Study everything we've covered” instead of listing specific topics.
Sometimes being noncommittal makes sense. If you're invited to two birthday parties on the same day, you might give a noncommittal answer to both friends until you figure out your schedule. Other times it frustrates people because they need a real answer to make their own plans.
Politicians are often accused of giving noncommittal responses to tough questions. Instead of taking a clear position, they might say something vague like “that's an important issue we're looking into.” A noncommittal answer avoids angering anyone but also avoids actually saying anything meaningful.
The opposite of being noncommittal is being decisive: making clear choices and sticking to them.