convenient
Easy and helpful because it saves time, effort, or trouble.
Convenient means easy to use, do, or reach because it fits well with your needs or schedule. A convenient time for a doctor's appointment is one that doesn't conflict with school or other activities. A convenient location for a library is one close to where you live, not across town. A convenient tool is one that makes a job simpler, like a backpack with many pockets that keeps everything organized and easy to find.
The word suggests that something saves you time, effort, or trouble. Microwaves are convenient because they heat food quickly. Online shopping is convenient because you can browse from home instead of driving to multiple stores. When your friend suggests meeting at a playground halfway between your houses, that's a convenient spot for both of you.
Sometimes people use convenient to describe timing that seems suspiciously perfect. If someone claims they “forgot” their homework on the day it was due, a teacher might say that's awfully convenient. This meaning suggests the person might be making excuses.
The opposite is inconvenient, something that causes extra hassle or doesn't fit well with your plans. A convenience is something that makes life easier, like the conveniences of modern life: electricity, running water, and refrigeration.